I was in the Navy and did many maneuvering watches in and out of port always with tugs alongside. It is a very dangerous job. They are very well trained and ALWAYS did a great job! They don't get the recognition they deserve.
I used to work on a cargo barge on the inside passage and thought we were pretty big until one day when we came around a corner and I was looking up at the bow of the Haida Warrior. That tug made us look like a row boat. Her sister ship is the Haida Chief.
I am a Tug Engineer in Australia, and I have often thought about this issue but struggled to get straight answers. This video is amazing and explains it perfectly. Thank you.
Yeah that continually variable pitch is really cool, conceptually like how helicopters do. From what I've googled, it's done via linkages instead of a swashplate.
Considering roalnddunk5054's point, I believe the linkage design is based on some later paddlewheel steamers that had a system to keep the paddles vertical while in the water, reducing losses from scooping water up or down and making them more efficient. But in effect it has the same purpose as a helicopter's swash plate, changing the angle of blades at different parts of their rotation to allow any direction of thrust. But in a horizontal rather than vertical axis.
@@xenn4985 I'm pretty sure it's not using a cam - a cam has followers and usually isn't used for simple harmonic or oscillating motion. To my understanding these use links attached to a collar that is on an eccentric of some sort, the position of that center point can be changed in two dimensions to change where the blades are angled forward and back. Mechanically it's more similar to a swashplate than a cam, but isn't a swashplate either. I guess it could be compared with a swashplate but working on radial displacement instead of axial tilt.
The release button problem reminds me of something that happened to my partner. She had a data center fire -- power shorted out through a data line and caused a modem to explode and catch fire. Just inside the machine room door, there's a Big Red Switch that cuts all power to the entire room, for just such an emergency. She ran into the room, saw the fire, and hit the Big Red Switch. Unfortunately, the contractors who'd built the room never actually hooked the Big Red Switch up to anything, absolutely nothing happened. She had to spend the next 15 minutes in a smoke-filled room shutting down all the server racks one by one.
@@ithecastic I'm against stupid wokeness, but calling ur SO a partner is a problem now? Are you okay? Partner predates any wokeness. 14th Century to be exact, you must be living in a different timeline.
I was a tugboat captain, 1850 hp twin screw designed for ocean towing in the Pacific. It was of utmost importance to check the hydraulic brake release to break free from the tow. Of course you throw out some towline and then you reset the brake and recover towing control. The hydraulic release is located at all steering stations. I always had a seaman stand by the manual release, with a vhf radio, as well. Most shi- handling tugs have a different setup but a quick release is mandatory. I have had the main deck watertight doors in the water several times as the barge got out of control, mostly in shallow waterways such as rivers with strong currents and limited maneuvering room. Things happen quickly when the current is strong. When both bridles are on the winch drum, ejecting the towline can be fatal as one bridle goes out quickly under tension while the other side creates large loops that can catch anything on deck including the working crew. If the bridle breaks at least you do not capsize but try controlling a barge, in a river, on a short line from one corner. Not a comfortable place to be. When you first become captain you have some breath taking experiences.
Fun Fact: On old conventional harbor tugs, I know of, the length of Gog-line was adjusted by a seperate winch. Therefore at slow speeds the tug could use its full turning ability, while at moderate speed the Gog line could be tightened which made it possible to be towed behind the ship safely. Conventional tugs otherwise really dont like to be towed astern, as mentioned in the video.
Recently saw a tug which had an interesting twist on this. Instead of a single gog line, they had two attached to each side of the ship and very close to the water line. This way they could not only use the line to limit the movement, but also to steer the tug when it's pulling.
I learned this the hard way even with an RC model tug... I tow myself in a 17-foot kayak (total weight 300lbs) with my 3½ft, 30-pound model tug. I learned right quick to position my tow bollard well back on the aft deck after very nearly sinking my $1500 model. Now I can get well into indirect towing, but if it gets away from me, all I have to do is let off the throttles and it will come back up and flop alongside.
1:29 That is the coolest thruster design I’ve ever seen and it’s so simple. I love it and I wonder how nobody ever thought of it before. Absolute genius.
If there's anything I've learned from watching your videos, it's that the marine industry employs a lot of physics every day to run safety and efficiently. I assume most captains, for example, don't need to know all the explicit physics like you show in these videos, but the fact that they do clearly have a general understanding of it, and shipbuilders clearly need to have a pretty in-depth understanding of the forces at play, is something I had never really though of before. I used to think "make boat a boat shape and slap engine in to make boat go".
If you look around at anything, physics are a major part of everything you do. Same is true of driving a car, though like you say of ship captains (probably even moreso) I'm sure most drivers, while having some awareness of this on some level, don't really understand in full detail. While car enthusiasts and especially racing drivers consider it a huge amount in how to win races. I've thought a lot about it for just how to stay alive to recover from frightening situations - for example between physics analysis and rallycross racing, I figured out that if my car is fishtailing the best move - in my specific car - is to literally let go of the steering wheel and let it straighten itself out. For a period of time I wanted to become a high school physics teacher, and I thought a lot of the physics all around us - while some teachers teach physics as math, math, and more math, I would show students places they've seen and encountered, or often used, the concepts in their own lives.
On my home river, the River Clyde, there's been several tugs lost when towing after capsizing. The primary reason for the loss of the vessels was that they weren't watertight at the point of capsize. Crews were lost because they didn't follow the rules. A very interesting explanation of the forces at work.
I work on a towboat and can confirm nothing good happens when a boat is held pinned or drug sideways through water or in current. Generally if you find yourself there alot of stuff has gone wrong and closed sealed water tight doors are about all that is going to save you, and it is still going to be a wild ride.
I'm a landlubber who always learns a lot from your episodes - thanks. Sounds like ALL tugs should be mandated to have a Quick Release system and a 'Standard' is required for documentation and signage.
Additionally. They make semi-truck pulling contests, tractor pulling contests, why do we not have tugboat pulling contests? Get 3-4 tugs who have to race pulling heavy barges across a 2 mile stretch of water!
I grew up on Peoria Lake on the Illinois, a navigable river used for a fair bit of barge traffic. I got to ride on one of two paddlewheels (restored originals, no longer burning coal) that staged a race for the bicentennial celebrations in 1976. If steam-powered paddlewheel river boats can have races, why cannot tug boat contests exist? Clearly a tug-of-rope contest is out of the question (insanely dangerous because of the stored energy in the line) but tugs pulling or pushing identical barges... I'd sign up to watch that!
One thing you didn't mention - there have been issues with the emergency release taking several seconds to activate (by which time it is too late). Usually because the emergency release was tested normally and worked fine, but when under load the system was underpowered to quickly release the line.
A few years ago I was rowing up the Tyne river and we watched a tug going astern all the way past us and carried on out of sight. I don't remember much details about the tug but I'd assume it's probably still at work now. I found it amusing that they didn't bother turning round
Ergonomics and crew knowledge are probably the two most important factors in any accident. The two Boeing 737 Max crashes that grounded the entire fleet are a great example. The angle of attack sensor on those two aircraft malfunctioned, causing the automated system to pitch the planes wildly as it was being fed incorrect data. All the pilots had to do was flip a switch that would take the automatic system offline and allow them to take manual control. This switch was in an out of the way spot where crews wouldn't notice it and, critically, the Boeing retraining documentation for pilots transitioning from the standard 737 to the Max never made mention of this override switch. Had the pilots know about it, either from it being placed in a prominent position in the console, it being mentioned in their training documentation, or preferably both, they would have easily been able to take control of the aircraft and no one would have died.
As someone who works on a tug, correction at 2:23 Almost all tugs have what are called “backing rudders” these are, albeit smaller, rudders that sit in front of the wheels (not propellers, those are for planes and tiny personal crafts) and provide steering when backing up. Most people use both the backing and steering rudders to use one engine in forward and reverse to turn on a dime or provide extra force to turn something being towed.
Concise and clear explanation - well done. Years ago I had the chance to tour the Master, the last steam tug in BC which was preserved as a working museum vessel and did a stop over in my city. The look around the engine riim was fascinating in particular. Whether harbour tugs or long distance tow boats these workhorses have always interested me.
Are there any automated quick release systems? It seems like an obvious solution, so I wonder if it is in use, or why not? You could put sensors on the ship that keep track of its angle and angular velocity and automatically release the rope if a critical threshold is crossed.
that'd shoot up accidental tug releases. if you get beamed by one wave and recover, but the tug line parted because the auto panic button was set to paranoid, you will have to get the tug line back on, which is difficult, and you'll have suddenly left a barge or ship without a source of maneuvering, potentially in an area which is congested or dangerous. it increases the odds that you'll live, but it increases the odds of a fuckup of smaller magnitude.
The sensors have to filter out A LOT of normal vessel movements to find the few that will cause issues. A good number of tugs work offshore and roll and pitch violently in rough weather. There are a lot of situations where cutting the tow line can cause a very dangerous situation. Also all of these sensors have to survive the marine environment. Tugs tend to vibrate a lot more than regular ships
Important topic. Offshore supply boats usually have some sort of framework that keeps any towline towing from the stern. It always seemed pretty obvious why they did this. I didn't realise tugs didn't have this same protection but you've explained the reason why quite well.
There is actually a good solution that would make it almost impossible to capsize a tug by pulling at the tug line. When I was active in the fail flight club we used a safety connector on the tow line that had a pre-calculated limit where it would break at. You could quite easily order one for the tug and the tug line would disconnect with the safety of you run the risk of capsizing the tug with one minor issue being wind or currents that might change the load on the tug line.
I suspect the problem is the force needed to capsize the tug if it's pulled sideways is probably less than the force the tug will apply on the line in a normal straight-ahead tow. This is different from the situation with, say, a glider winch tow, where you're just trying to avoid exceeding the airframe stress limits.
You know, I've been thinking about tug boats lately. Tug boats are like the unsung heroes of the maritime world. They're out there, just tugging away, pulling these massive ships around like it's no big deal. I mean, think about it. It's like the ultimate power move on the water. But you know what's really bugging me? How do tug boats even get into the business? Did they have some sort of tugging internship? Did they graduate from tug boat school with honors? I can picture it now: "Congratulations, you've earned your degree in Advanced Tugology!" And what's their career progression like? Do they start with tiny toys in the bathtub, and then work their way up to bigger rubber duckies? Maybe they have tug boat idols they look up to. You know, posters of legendary tuggers on their bedroom walls - "Tugboat Legends: Pulling through the Ages!" But let's talk about the name, "tug boat." Isn't it a little too on the nose? Like, why not call it a "strong boat" or a "mighty boat"? I feel like tug boats should have their own PR agent to give them a catchier name. Imagine introducing them like, "Ladies and gentlemen, the incredible, the invincible, the unstoppable... SUPER TUG!" I'd be way more excited to see a "Super Tug" in action. And you know what's even crazier? They have these little tug boats that tow gigantic cargo ships across oceans. It's like watching a chihuahua pulling a semi-truck. It defies all logic. But hey, they get the job done, so kudos to them. In the end, I guess tug boats are like the Clark Kents of the water - humble, unassuming, but incredibly powerful when duty calls. So here's to all the tug boat operators out there - keep tugging away and reminding us that even the smallest boats can make the biggest waves!
Sounds to me like having a live feed between the two ship bridges is a requirement. Any control change on one ship should be immediately communicated to the other ship. To go along with that would be clear unambiguous code phrases that, when used correctly, speed up the communication process and reduce misunderstandings.
Perhaps you could make a video sometime about harbour pilots? What they do, why they're improtant to even experienced captains, why they're still used despite modern communication and navigation technologies etc. etc.
"If there are multiple tugs available, consider which is best in each position" These are wise words. Grip strength usually plays a part in it. Of course if one tug simply can't do it in that position, two tugs in the same position will almost certainly launch the seamen.
I actually had a ring side seat to see a very similar situation develop back in 1977 as a US Navy Tug assisted a Spanish carrier get underway in Rota Spain. The carrier (helicopter carrier) so not like the Nimitz in size, was pulled away from the pier and kicked it into overdrive before releasing the tow line. The Tug Boat was dragged backwards and the captain tried to run in reverse fast enough to be able to unhook from his end but was not able. He quickly did a hard right rudder turning the tug sideways and the tow line parted. They almost turned over but didn't. The tug crew was running for cover and slamming hatches. I stood right there and watched the whole thing start to finish.
Seems like the obvious solution is an automated tow-cutting system that uses a gyro or two to automatically cut the line whenever the tug tilts/lists by more than X degrees.
I can't see why they don't already have such a feature, even if they want to keep the quick release on human input, the least it could do is turn on a big red flashy light right above the quick release button when it hits a dangerous angle
It seems like the quick release could be tied into the gogs where the line cuts if the gogs are pulled too hard. You would still have the manual option, but it would trigger the release when it happens too fast for the crew to react. Ideally it would also need a mechanism to avoid the line wrapping around anything when released, but I don't know if that's a solved problem or not.
How about having a very strong samurai with a katana next to the line to cut it when you need to release it fast? As we all know from countless films and animes, a protagonist could cut metal with one swing no matter the strength of the cable, so it could be an instant release (minus the time it takes him to scream the name of the attack)
Red jasmine in Glasgow Clyde comes to mind. Engine room door was open. I drove a tug for 10 mins and did a few circles etc and docking manoeuvres on a floating pontoon thing. crazy the directions it can go.
I'm a retired pilot on the river Schelde to and from the port of Antwerp. I have 2 comments: 1. It is good seamanship to prevent the tug when you want to start te engine off course. But even without warning : the tugboat captain can see the wash coming from under the stern when the engine has been started, and it takes a while till the ship actually will take some speed. 2. The manoever leaving the berth with current from the bow: it is wrong to try and leave stern first ! You should take the bow out first, and let the current do its job. The tug only has to take care that the stern will not hit the quay again. Or take the tug foreward, keep sternspring, put rudder hard over towards the quay and when the bow is coming off give a kick ahead if the current + rudder is not enough to keep the stern free from the quay.
In the past tugs used to have a hook for towing, that had a quick release function. Nowadays firtually all tugs tow with their towing line on the winch. Which cannot be quick released. Additianolly; As i've watched many tugboats, from the deck of a merchant. I've never seen a tug with all hatches closed and secured....
@@MrBirdnose No, the clutch of the winch will be released when you press the big red emergency release Button. The line spools off without tension, and the bitter end will Break free.
Quick release system for a line under a few hundred tons of tensions sounds like a safe and reasonable thing to have. Not a line handling hazard waiting to happen. Well, better than capsizing I guess, lol.
Pretty negligent to not have a quick release system. Seen them used in some incredibly heavy and dynamic loads, so I know it's not an engineering issue.
All of the rugs I know have the connection at about a third from the rear. This gives plenty of manoeuvrability but helps a lot to prevent any danger. It’s still possible though, just a lot less likely. I own a now recreational tug build in 1887 and it to has the connection at about a third from the rear. Apparently they already knew back then.
An interesting solution to this problem is the carousel tug. The towing connection sits on a ring around the superstructure of the tug meaning it can rotate around the tug giving it super manoeuvrability yet since the towing connection sits off-center when the tow line starts pulling the tug sideways it actually pulls it more upright increasing stability. Nova tug has been building the latest innovations in these type of tugs with the carrousel rave tug. Their website had some really nice video’s and articles about how the forces work to completely eliminate the risk of capsize
I didnt see any mention of the winchs and the "quick release" system on these winches called the winch breaks. The majority of tugs in this type of industry aren't typically made fast to the object they are towing\tugging.....they will pass a small line up to the ship and have the crew on the ship haul the main line up to the anchor point where the tug will be attached to the ship. Where the other end of the main line or "towline" would be attached to the tug via a mechanical winch. Winch's that are typically fitted with 3000 to 4000 foot towline. The winch is equipped with a breaking system. These breaks can be released instantly. These breaks are tested to the bolard pull of the tug that these said winch's are installed on so not to slip while being used durring bursts of maximum power. The breaking system is not designed to be used while on a long haul. By long haul.... i am referimg to trips for days at sea under maximum power to get from point A to point B. Once you are set out for a trip. All safety measures and avoidance of all questionable areas the tug would be in. You would then lock down the break and set the "dog" on said winch. At this point there is no "quick release".
5: 53 i suppose you could just have a blade at each end of the Gog protected by a bit of metal that would in normal use stop the rope from hitting the blade but that would fail under this sort of stress and let the rope be cut
Wouldn't another solution be to have the attachment point be slightly towards the stern from the middle of the tug? That way, if the tug gets tugged, it turns like a weathervane instead of capsizing.
It'd be called a weak link rather than a fuse in this application, same idea though. They're not used here because parting the tow line is a worse scenario in most situations. The forces applied in normal operations is greater than those applied in an abnormal situation which could cause capsizing (in most scenarios), causing way more danger due to unintentional breaking of this weak link. Lines like this should be hooked to a winch with a one button "abort" used to let the winch freewheel imho. For the amount of times emergency aborts are needed vs how much chaos weak links would cause, it's better to not introduce something more than can go wrong. Weak links are for life rafts, not tow lines.
Do the emergency release systems have automatic tension sensors to give skippers a pre warning? Might not be economical for smaller workboat towing vessels, but surely large towage operators can have something fitted. A large vessel breaking away may cause some grief, but nothing compared to whole tug crews wiped out in an instant.
The video mentions that the gog has to be well measured, but does it have to be a fixed length? I'm imagining a setup with the line attached to a high-powered winch fixed at the stern, under normal conditions it could be fairly long connecting cable allowing plenty of movement, but as soon as instability was detected the winch could rapidly reel in the cable, pinning the main tow line directly astern and imparting a torque to rotate the ship and restore some stability. Easily resettable too, just allow the winch to wind out some more cable. Potentially a computer could constantly monitor it and constantly change the length depending on sensor input.
So, the classic, quintessential, turn of the century tugboat had one screw, one rudder, and the towline was attached 3/4 of the way down the hull length. How is it that they managed as well as they did with this arrangement? Was there just a completely different tow & handlining theory?
I don‘t know if this is the story he‘s referring to (I think my example happened earlier than that), but in Scotland, a tug named „Flying Phantom“ was capsized after it had beached in think fog and being pulled over by the Red Jasmine (I believe a large bulk carrier). I believe three crew members died, one survived. When investigating, they found that the emergency release systems were only tested when there was no actual tension on the rope, but when under tension, it could take up to eight seconds between pushing the button and the rope being released. Additionally, not all hatches and doors were closed on the Flying Phantom, leading to it immediately sinking on the spot… Edit: I looked it up (there‘s a whole Wikipedia article on that tug), the accident happened on the 19th of December 2007. The rest of my above information was correct :)
It doesn't seem like it would be that difficult to automate the quick-release system to trigger in critical situations.
It’s called a guy with an ax. But when that hawse parts, it’s a missle
@@mikepotter6426My ex-boss was a tug hand and said the same thing you said. Seems like he wasn’t kidding me after all.
@mikepotter6426 Even if it didn't have parts, I'd still be staying far from that tow rope! Imagine you don't make a clean cut...
Exactly my thinking. Just have a mechanical system where the tow line is automatically released if the tug ever tilts more than X amount.
@@superslash7254 Every extra mechanical step is just another point of failure.
I feel working on a tugboat might be more dangerous than it seems at first glance. Capsizing, lines snapping, bad weather...
True
I was in the Navy and did many maneuvering watches in and out of port always with tugs alongside. It is a very dangerous job. They are very well trained and ALWAYS did a great job! They don't get the recognition they deserve.
Or get hit by massive anchors
I used to work on a cargo barge on the inside passage and thought we were pretty big until one day when we came around a corner and I was looking up at the bow of the Haida Warrior. That tug made us look like a row boat. Her sister ship is the Haida Chief.
I am a Tug Engineer in Australia, and I have often thought about this issue but struggled to get straight answers. This video is amazing and explains it perfectly. Thank you.
Have you heard of tugboats getting hit with a anchor
That Voith drive is interesting... it's like they took the helicopter swash plate concept and applied it to aquatic propulsion.
It is similar to paddle ship wheel taken from the side and put underneath but with continual variable pitch blades.I was ch/eng in one for 15 years.
Yeah that continually variable pitch is really cool, conceptually like how helicopters do. From what I've googled, it's done via linkages instead of a swashplate.
Considering roalnddunk5054's point, I believe the linkage design is based on some later paddlewheel steamers that had a system to keep the paddles vertical while in the water, reducing losses from scooping water up or down and making them more efficient. But in effect it has the same purpose as a helicopter's swash plate, changing the angle of blades at different parts of their rotation to allow any direction of thrust. But in a horizontal rather than vertical axis.
@@quillmaurer6563 cam... the mechanism you people are talking about is a cam.
@@xenn4985 I'm pretty sure it's not using a cam - a cam has followers and usually isn't used for simple harmonic or oscillating motion. To my understanding these use links attached to a collar that is on an eccentric of some sort, the position of that center point can be changed in two dimensions to change where the blades are angled forward and back. Mechanically it's more similar to a swashplate than a cam, but isn't a swashplate either. I guess it could be compared with a swashplate but working on radial displacement instead of axial tilt.
The release button problem reminds me of something that happened to my partner. She had a data center fire -- power shorted out through a data line and caused a modem to explode and catch fire. Just inside the machine room door, there's a Big Red Switch that cuts all power to the entire room, for just such an emergency. She ran into the room, saw the fire, and hit the Big Red Switch.
Unfortunately, the contractors who'd built the room never actually hooked the Big Red Switch up to anything, absolutely nothing happened. She had to spend the next 15 minutes in a smoke-filled room shutting down all the server racks one by one.
Damn. Did the contractor get sued or anything? And of course, was your partner okay?
Tug my chub Tactical Navigation
@@ithecastic I'm against stupid wokeness, but calling ur SO a partner is a problem now? Are you okay? Partner predates any wokeness. 14th Century to be exact, you must be living in a different timeline.
@@dusteyezz784wokeness doesn't really exist... It's just made up by snowflakes boomer who wants to get mad about everything.
@@ithecastic "for the sake of the woke mob?" and you're only one here bitching about it, lol. That's sad man. :D
I was a tugboat captain, 1850 hp twin screw designed for ocean towing in the Pacific. It was of utmost importance to check the hydraulic brake release to break free from the tow. Of course you throw out some towline and then you reset the brake and recover towing control. The hydraulic release is located at all steering stations. I always had a seaman stand by the manual release, with a vhf radio, as well. Most shi- handling tugs have a different setup but a quick release is mandatory. I have had the main deck watertight doors in the water several times as the barge got out of control, mostly in shallow waterways such as rivers with strong currents and limited maneuvering room. Things happen quickly when the current is strong. When both bridles are on the winch drum, ejecting the towline can be fatal as one bridle goes out quickly under tension while the other side creates large loops that can catch anything on deck including the working crew. If the bridle breaks at least you do not capsize but try controlling a barge, in a river, on a short line from one corner. Not a comfortable place to be. When you first become captain you have some breath taking experiences.
Fun Fact: On old conventional harbor tugs, I know of, the length of Gog-line was adjusted by a seperate winch. Therefore at slow speeds the tug could use its full turning ability, while at moderate speed the Gog line could be tightened which made it possible to be towed behind the ship safely. Conventional tugs otherwise really dont like to be towed astern, as mentioned in the video.
Recently saw a tug which had an interesting twist on this. Instead of a single gog line, they had two attached to each side of the ship and very close to the water line. This way they could not only use the line to limit the movement, but also to steer the tug when it's pulling.
I think that "Plan ahead" part should be the takeaway for those who care but don't want to make a hobby of it.
I learned this the hard way even with an RC model tug... I tow myself in a 17-foot kayak (total weight 300lbs) with my 3½ft, 30-pound model tug. I learned right quick to position my tow bollard well back on the aft deck after very nearly sinking my $1500 model. Now I can get well into indirect towing, but if it gets away from me, all I have to do is let off the throttles and it will come back up and flop alongside.
1:29 That is the coolest thruster design I’ve ever seen and it’s so simple. I love it and I wonder how nobody ever thought of it before. Absolute genius.
The quality of the content and the animations of this channel never cease to amaze me. Thank you so much!
If there's anything I've learned from watching your videos, it's that the marine industry employs a lot of physics every day to run safety and efficiently. I assume most captains, for example, don't need to know all the explicit physics like you show in these videos, but the fact that they do clearly have a general understanding of it, and shipbuilders clearly need to have a pretty in-depth understanding of the forces at play, is something I had never really though of before. I used to think "make boat a boat shape and slap engine in to make boat go".
You are not ready to hear about planes.
If you look around at anything, physics are a major part of everything you do. Same is true of driving a car, though like you say of ship captains (probably even moreso) I'm sure most drivers, while having some awareness of this on some level, don't really understand in full detail. While car enthusiasts and especially racing drivers consider it a huge amount in how to win races. I've thought a lot about it for just how to stay alive to recover from frightening situations - for example between physics analysis and rallycross racing, I figured out that if my car is fishtailing the best move - in my specific car - is to literally let go of the steering wheel and let it straighten itself out. For a period of time I wanted to become a high school physics teacher, and I thought a lot of the physics all around us - while some teachers teach physics as math, math, and more math, I would show students places they've seen and encountered, or often used, the concepts in their own lives.
On my home river, the River Clyde, there's been several tugs lost when towing after capsizing. The primary reason for the loss of the vessels was that they weren't watertight at the point of capsize. Crews were lost because they didn't follow the rules. A very interesting explanation of the forces at work.
I work on a towboat and can confirm nothing good happens when a boat is held pinned or drug sideways through water or in current. Generally if you find yourself there alot of stuff has gone wrong and closed sealed water tight doors are about all that is going to save you, and it is still going to be a wild ride.
Russell Crowe made a tug boat named "Tugger" attempt to kill itself by singing one of his songs to it.
MAKING MOVIES MAKING SONGS AND FOITIN' ROUND THE WORLD
I think you will find him named Tuggah!
I'm a landlubber who always learns a lot from your episodes - thanks.
Sounds like ALL tugs should be mandated to have a Quick Release system and a 'Standard' is required for documentation and signage.
Additionally. They make semi-truck pulling contests, tractor pulling contests, why do we not have tugboat pulling contests? Get 3-4 tugs who have to race pulling heavy barges across a 2 mile stretch of water!
I grew up on Peoria Lake on the Illinois, a navigable river used for a fair bit of barge traffic. I got to ride on one of two paddlewheels (restored originals, no longer burning coal) that staged a race for the bicentennial celebrations in 1976. If steam-powered paddlewheel river boats can have races, why cannot tug boat contests exist? Clearly a tug-of-rope contest is out of the question (insanely dangerous because of the stored energy in the line) but tugs pulling or pushing identical barges... I'd sign up to watch that!
Dangerous work. You always want to hire a pro for your tug jobs.
Yeah. I hate it when they start going to work, and then just roll over half way through the job.
Hire a pro and you will find it quite a relief.
One thing you didn't mention - there have been issues with the emergency release taking several seconds to activate (by which time it is too late).
Usually because the emergency release was tested normally and worked fine, but when under load the system was underpowered to quickly release the line.
Sounds like they need to design and test them under load. Preferably, a load higher than the standard tug line itself, can physically support.
love to switch to the home page to see you uploaded 1 minute ago
0:27 There are really two things a tugboat needs to be able to do well:
1. Tug
2. Boat
What another goofy topic. I love it. Your content is unique and lovely
A few years ago I was rowing up the Tyne river and we watched a tug going astern all the way past us and carried on out of sight. I don't remember much details about the tug but I'd assume it's probably still at work now. I found it amusing that they didn't bother turning round
Ergonomics and crew knowledge are probably the two most important factors in any accident. The two Boeing 737 Max crashes that grounded the entire fleet are a great example. The angle of attack sensor on those two aircraft malfunctioned, causing the automated system to pitch the planes wildly as it was being fed incorrect data. All the pilots had to do was flip a switch that would take the automatic system offline and allow them to take manual control. This switch was in an out of the way spot where crews wouldn't notice it and, critically, the Boeing retraining documentation for pilots transitioning from the standard 737 to the Max never made mention of this override switch.
Had the pilots know about it, either from it being placed in a prominent position in the console, it being mentioned in their training documentation, or preferably both, they would have easily been able to take control of the aircraft and no one would have died.
As someone who works on a tug, correction at 2:23
Almost all tugs have what are called “backing rudders” these are, albeit smaller, rudders that sit in front of the wheels (not propellers, those are for planes and tiny personal crafts) and provide steering when backing up. Most people use both the backing and steering rudders to use one engine in forward and reverse to turn on a dime or provide extra force to turn something being towed.
Concise and clear explanation - well done. Years ago I had the chance to tour the Master, the last steam tug in BC which was preserved as a working museum vessel and did a stop over in my city. The look around the engine riim was fascinating in particular. Whether harbour tugs or long distance tow boats these workhorses have always interested me.
Awesome! So many of your videos taught me things I never even realized I'd want to know. Great stuff!
Are there any automated quick release systems? It seems like an obvious solution, so I wonder if it is in use, or why not?
You could put sensors on the ship that keep track of its angle and angular velocity and automatically release the rope if a critical threshold is crossed.
that'd shoot up accidental tug releases. if you get beamed by one wave and recover, but the tug line parted because the auto panic button was set to paranoid, you will have to get the tug line back on, which is difficult, and you'll have suddenly left a barge or ship without a source of maneuvering, potentially in an area which is congested or dangerous.
it increases the odds that you'll live, but it increases the odds of a fuckup of smaller magnitude.
The sensors have to filter out A LOT of normal vessel movements to find the few that will cause issues. A good number of tugs work offshore and roll and pitch violently in rough weather. There are a lot of situations where cutting the tow line can cause a very dangerous situation. Also all of these sensors have to survive the marine environment. Tugs tend to vibrate a lot more than regular ships
SO INTERESTING! I've wondered about this for years. Thank you for posting!
"The tug boat, for it size, is the most powerful craft afloat."
Our 40ft line boat only had a single Kort nozzle and no bow thruster. I learned a lot about ship handling on the little boat.
Important topic. Offshore supply boats usually have some sort of framework that keeps any towline towing from the stern. It always seemed pretty obvious why they did this. I didn't realise tugs didn't have this same protection but you've explained the reason why quite well.
Another great, informative and well presented video. Thank you
There is actually a good solution that would make it almost impossible to capsize a tug by pulling at the tug line. When I was active in the fail flight club we used a safety connector on the tow line that had a pre-calculated limit where it would break at. You could quite easily order one for the tug and the tug line would disconnect with the safety of you run the risk of capsizing the tug with one minor issue being wind or currents that might change the load on the tug line.
I suspect the problem is the force needed to capsize the tug if it's pulled sideways is probably less than the force the tug will apply on the line in a normal straight-ahead tow.
This is different from the situation with, say, a glider winch tow, where you're just trying to avoid exceeding the airframe stress limits.
Tugging too hard is definitely dangerous for many reasons!
Dangerous if done incorrectly but sometimes it’s essential
I'm glad I was not the only one with a juvenile mind.
Getting tugged off with a proper tug line. An experienced tugger is essential.
You know, I've been thinking about tug boats lately. Tug boats are like the unsung heroes of the maritime world. They're out there, just tugging away, pulling these massive ships around like it's no big deal. I mean, think about it. It's like the ultimate power move on the water.
But you know what's really bugging me? How do tug boats even get into the business? Did they have some sort of tugging internship? Did they graduate from tug boat school with honors? I can picture it now: "Congratulations, you've earned your degree in Advanced Tugology!"
And what's their career progression like? Do they start with tiny toys in the bathtub, and then work their way up to bigger rubber duckies? Maybe they have tug boat idols they look up to. You know, posters of legendary tuggers on their bedroom walls - "Tugboat Legends: Pulling through the Ages!"
But let's talk about the name, "tug boat." Isn't it a little too on the nose? Like, why not call it a "strong boat" or a "mighty boat"? I feel like tug boats should have their own PR agent to give them a catchier name. Imagine introducing them like, "Ladies and gentlemen, the incredible, the invincible, the unstoppable... SUPER TUG!" I'd be way more excited to see a "Super Tug" in action.
And you know what's even crazier? They have these little tug boats that tow gigantic cargo ships across oceans. It's like watching a chihuahua pulling a semi-truck. It defies all logic. But hey, they get the job done, so kudos to them.
In the end, I guess tug boats are like the Clark Kents of the water - humble, unassuming, but incredibly powerful when duty calls. So here's to all the tug boat operators out there - keep tugging away and reminding us that even the smallest boats can make the biggest waves!
Low effort ChatGPT
@@ttjoseph1They graduate from the same maritime schools as big ship captains or harbor pilots. Tug specific stuff are learned on the job
Sounds to me like having a live feed between the two ship bridges is a requirement. Any control change on one ship should be immediately communicated to the other ship. To go along with that would be clear unambiguous code phrases that, when used correctly, speed up the communication process and reduce misunderstandings.
Your animations are outstanding! You do a really good job of simplifying things to make them understandable
Perhaps you could make a video sometime about harbour pilots? What they do, why they're improtant to even experienced captains, why they're still used despite modern communication and navigation technologies etc. etc.
"If there are multiple tugs available, consider which is best in each position"
These are wise words. Grip strength usually plays a part in it.
Of course if one tug simply can't do it in that position, two tugs in the same position will almost certainly launch the seamen.
Hi Casnav!
These animations are the best!
Always thought Tugs were more complicated than I knew. I was right, very interesting.
gives insight to a lot more respect for reputable tug services and danger of their duties.
This video *tugged* at my heartstrings. Thank you
"Excuse me. Did you say blades?" "Yes. Rotating ones."
That is called "tripping the tug". It is as dangerous as it seems.
Fantastic episode, thanks for posting!
Here in Australia we’re experts in gerting…. it’s even in our national anthem “our home is girt by sea” 😊
Yep. I think only us Aussies will get your joke 😂
I actually had a ring side seat to see a very similar situation develop back in 1977 as a US Navy Tug assisted a Spanish carrier get underway in Rota Spain.
The carrier (helicopter carrier) so not like the Nimitz in size, was pulled away from the pier and kicked it into overdrive before releasing the tow line. The Tug Boat was dragged backwards and the captain tried to run in reverse fast enough to be able to unhook from his end but was not able. He quickly did a hard right rudder turning the tug sideways and the tow line parted. They almost turned over but didn't. The tug crew was running for cover and slamming hatches.
I stood right there and watched the whole thing start to finish.
Seems like the obvious solution is an automated tow-cutting system that uses a gyro or two to automatically cut the line whenever the tug tilts/lists by more than X degrees.
I can't see why they don't already have such a feature, even if they want to keep the quick release on human input, the least it could do is turn on a big red flashy light right above the quick release button when it hits a dangerous angle
It seems like the quick release could be tied into the gogs where the line cuts if the gogs are pulled too hard. You would still have the manual option, but it would trigger the release when it happens too fast for the crew to react.
Ideally it would also need a mechanism to avoid the line wrapping around anything when released, but I don't know if that's a solved problem or not.
How about having a very strong samurai with a katana next to the line to cut it when you need to release it fast? As we all know from countless films and animes, a protagonist could cut metal with one swing no matter the strength of the cable, so it could be an instant release (minus the time it takes him to scream the name of the attack)
Thank you RUclips recommendations, one day I shall get to use this knowledge about tug boats.
The USS Houston SSN-713 accidentally caught the cable between a barge and tug, pulled the tug under. about 1988
Red jasmine in Glasgow Clyde comes to mind. Engine room door was open. I drove a tug for 10 mins and did a few circles etc and docking manoeuvres on a floating pontoon thing. crazy the directions it can go.
DISASTERS AT SEA: S3E6 - Towed Under
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@@alandship its a doc about a boat that was tugged too hard. google it.
great video I'll be glad if you can do more videos on tug handling
At last, a video where I understood everything
The animations helped me.
my man why are you making a video about tugs capsizing and not on those voith drives, super neat
I'm a retired pilot on the river Schelde to and from the port of Antwerp. I have 2 comments: 1. It is good seamanship to prevent the tug when you want to start te engine off course. But even without warning : the tugboat captain can see the wash coming from under the stern when the engine has been started, and it takes a while till the ship actually will take some speed. 2. The manoever leaving the berth with current from the bow: it is wrong to try and leave stern first ! You should take the bow out first, and let the current do its job. The tug only has to take care that the stern will not hit the quay again. Or take the tug foreward, keep sternspring, put rudder hard over towards the quay and when the bow is coming off give a kick ahead if the current + rudder is not enough to keep the stern free from the quay.
4:11 keeping you towing point below your meta static height would also help but is ..admittedly somewhat impractical in most cases
In the past tugs used to have a hook for towing, that had a quick release function. Nowadays firtually all tugs tow with their towing line on the winch. Which cannot be quick released.
Additianolly; As i've watched many tugboats, from the deck of a merchant. I've never seen a tug with all hatches closed and secured....
incorrect the towing winches on harbor tugs have a quick release function
@@edgar5608 Is it a guillotine type mechanism to cut the line? I've seen those on glider tow winches.
@@MrBirdnose No, the clutch of the winch will be released when you press the big red emergency release Button. The line spools off without tension, and the bitter end will Break free.
Very clear animations!
Fun stuff. It makes me miss my kinematics and dynamics courses.
Quick release system for a line under a few hundred tons of tensions sounds like a safe and reasonable thing to have. Not a line handling hazard waiting to happen. Well, better than capsizing I guess, lol.
Pretty negligent to not have a quick release system. Seen them used in some incredibly heavy and dynamic loads, so I know it's not an engineering issue.
All of the rugs I know have the connection at about a third from the rear. This gives plenty of manoeuvrability but helps a lot to prevent any danger. It’s still possible though, just a lot less likely.
I own a now recreational tug build in 1887 and it to has the connection at about a third from the rear. Apparently they already knew back then.
Great video - thankyou!
What you call girding, I've seen called tripping in US tug operations.
An interesting solution to this problem is the carousel tug. The towing connection sits on a ring around the superstructure of the tug meaning it can rotate around the tug giving it super manoeuvrability yet since the towing connection sits off-center when the tow line starts pulling the tug sideways it actually pulls it more upright increasing stability. Nova tug has been building the latest innovations in these type of tugs with the carrousel rave tug. Their website had some really nice video’s and articles about how the forces work to completely eliminate the risk of capsize
All this gog line business sounds a lot like the way the mainsheet traveler works on some boomless rigs, fine-tuning the sheet angles.
How are the hitching "bollards" on the tug fastened down? Big bolts, fancy welding?
Just regular welding usually
@@aaaa-bz3ft Tx
Cool you mentioned the George H. Ledcor incident. It happened near where I am from!
Hey! Casual Navigation, I suggest you to tell us all about Voith Schneider Propellers, it would be interesting to see
Love the video. But that title is perfect..all I could think was ‘Is that what the cool kids call it now?’
I'm all agog at your excellent work.
👍🏽
5:02 Wont the force also turn the ship, preventing it from being towed sideways?
Needs an international standards body like for aviation so that cockpit / bridge signs and controls follow a well-designed universal pattern.
I tug my tugger multiple times a day
I didnt see any mention of the winchs and the "quick release" system on these winches called the winch breaks.
The majority of tugs in this type of industry aren't typically made fast to the object they are towing\tugging.....they will pass a small line up to the ship and have the crew on the ship haul the main line up to the anchor point where the tug will be attached to the ship. Where the other end of the main line or "towline" would be attached to the tug via a mechanical winch. Winch's that are typically fitted with 3000 to 4000 foot towline. The winch is equipped with a breaking system. These breaks can be released instantly. These breaks are tested to the bolard pull of the tug that these said winch's are installed on so not to slip while being used durring bursts of maximum power.
The breaking system is not designed to be used while on a long haul. By long haul.... i am referimg to trips for days at sea under maximum power to get from point A to point B.
Once you are set out for a trip. All safety measures and avoidance of all questionable areas the tug would be in. You would then lock down the break and set the "dog" on said winch. At this point there is no "quick release".
Has anyone heard of "gerting" referred to as "tripping"? Or "tripping" something different entirely?
Tugs can be set up so that way if the boat finds insleft in danger is can release the rope thing automatically
So it's essentially possible to jack knife a tugboat
It would be interesting to learn about carousel tugs.
5: 53 i suppose you could just have a blade at each end of the Gog protected by a bit of metal that would in normal use stop the rope from hitting the blade but that would fail under this sort of stress and let the rope be cut
2:21 Why would azimuth proppelers have rudders? Where are the rudders on this tug boat?
Considering you had an example of an unpowered barge causing a capsize, clearly communications between the vessels isn't a catch-all XD
Quick question, what happened with the crew of those two tugs?
Wouldn't another solution be to have the attachment point be slightly towards the stern from the middle of the tug?
That way, if the tug gets tugged, it turns like a weathervane instead of capsizing.
The Title on the Thumbnail is very relatable 🗿
I was going to ask, how safe are all these fittings? Could tow lines have a 'fuse'?
It'd be called a weak link rather than a fuse in this application, same idea though.
They're not used here because parting the tow line is a worse scenario in most situations. The forces applied in normal operations is greater than those applied in an abnormal situation which could cause capsizing (in most scenarios), causing way more danger due to unintentional breaking of this weak link.
Lines like this should be hooked to a winch with a one button "abort" used to let the winch freewheel imho. For the amount of times emergency aborts are needed vs how much chaos weak links would cause, it's better to not introduce something more than can go wrong.
Weak links are for life rafts, not tow lines.
Do the emergency release systems have automatic tension sensors to give skippers a pre warning? Might not be economical for smaller workboat towing vessels, but surely large towage operators can have something fitted. A large vessel breaking away may cause some grief, but nothing compared to whole tug crews wiped out in an instant.
Very informative!
Captain could wear a boat flip over button on a lanyard like a life alert and release all load
The video mentions that the gog has to be well measured, but does it have to be a fixed length? I'm imagining a setup with the line attached to a high-powered winch fixed at the stern, under normal conditions it could be fairly long connecting cable allowing plenty of movement, but as soon as instability was detected the winch could rapidly reel in the cable, pinning the main tow line directly astern and imparting a torque to rotate the ship and restore some stability.
Easily resettable too, just allow the winch to wind out some more cable. Potentially a computer could constantly monitor it and constantly change the length depending on sensor input.
So, the classic, quintessential, turn of the century tugboat had one screw, one rudder, and the towline was attached 3/4 of the way down the hull length. How is it that they managed as well as they did with this arrangement? Was there just a completely different tow & handlining theory?
Remote quick releases are better anyway
A remote transmitter that the crew can carry
Just pop open the cover and press the release like a trigger
Check the multratug 32 and 33 those are the most safe tugs there are
So what happened to the tug and crew in this specific case?
I don‘t know if this is the story he‘s referring to (I think my example happened earlier than that), but in Scotland, a tug named „Flying Phantom“ was capsized after it had beached in think fog and being pulled over by the Red Jasmine (I believe a large bulk carrier). I believe three crew members died, one survived.
When investigating, they found that the emergency release systems were only tested when there was no actual tension on the rope, but when under tension, it could take up to eight seconds between pushing the button and the rope being released. Additionally, not all hatches and doors were closed on the Flying Phantom, leading to it immediately sinking on the spot…
Edit: I looked it up (there‘s a whole Wikipedia article on that tug), the accident happened on the 19th of December 2007. The rest of my above information was correct :)