The choppers are fitted on an eccentric shaft with a ‘bob weight’ on the outside. With the weight pointing down, the couplings are at their closest with the faces touching. What you are seeing is the weight of the train acting on the eccentric, which lengthens the coupling slightly and absorbs a small amount of energy. Once the forces on the coupling even out, the weight will drop back down and bring the coupling faces back together.
Fascinating depiction of the slack action of the loose slate wagons, thank you! How far behind the down working did Blanche follow each time? Also, did the up AGM cross the down Mountaineer at Tanygrisiau or did it go into the second platform at Blaenau? Thanks again \m/
The first train was a struggle because the rails were wet and the low cloud covered everything in a fine wet coating. However the afternoon train was fine.
We usually use a double Fairlie on demonstration slate trains like this but Merddin Emrys was needed for a service train and David Lloyd George is still being rebuilt.
@@FfestiniogWelshHighland perhaps it is forgotten that these demonstration gravity trains have loads already onboard on the upward journey, which fact increases the necessary power \m/
Fabulous filming - thanks for sharing this. The gravity train must be an incredible experience! (Glad I'm not the one to do the FTR exams)
Excellent, bumper edition!
Jenny reminds me of a Austrian Stainz loco just a bit smaller 😊
Awesome
What happened to the chopper at 15:55? i've never seen that type of mech or action before??
Lyd has L&B style Norwegian chopper couplings which are compatible with standard F&WHR ones.
The choppers are fitted on an eccentric shaft with a ‘bob weight’ on the outside. With the weight pointing down, the couplings are at their closest with the faces touching. What you are seeing is the weight of the train acting on the eccentric, which lengthens the coupling slightly and absorbs a small amount of energy. Once the forces on the coupling even out, the weight will drop back down and bring the coupling faces back together.
Fascinating depiction of the slack action of the loose slate wagons, thank you! How far behind the down working did Blanche follow each time? Also, did the up AGM cross the down Mountaineer at Tanygrisiau or did it go into the second platform at Blaenau? Thanks again \m/
Blanche was about 30 minutes behind and they crossed at Tanygrisiau.
Can we get a driver's eye (even though there isn't really one 😅) view of the whole gravity train journey? That would be fascinating.
We’ll see what we can do.
COWS!! This was a fun video to film…
gravity trains are bumpy!!!
Mooooving pictures.
Nice to give the little engines a good run.
Did Blanche handle the slate train okay? She’s slipping an awful lot in the footage. I can’t imagine substituting for a fairlie is an easy job 😅
The first train was a struggle because the rails were wet and the low cloud covered everything in a fine wet coating. However the afternoon train was fine.
@@FfestiniogWelshHighland good to hear! Those wet rails can be a struggle sometimes.
I don’t think they ever use the double fairlies on freight…in modern times that is. 3:31
We usually use a double Fairlie on demonstration slate trains like this but Merddin Emrys was needed for a service train and David Lloyd George is still being rebuilt.
@@FfestiniogWelshHighland perhaps it is forgotten that these demonstration gravity trains have loads already onboard on the upward journey, which fact increases the necessary power \m/