71000

Did it do any fast running whilst on the SVR? even when being towed, bearing can always run warm, especially if the lubrication isn't quite set up right, or somewhere something gets blocked, and stops the feed

 

71000 has roller bearings.

 

Even Roller bearings need lube, at least once.

 

Fast work by support crew..... looks like 2h20m to gain a block, inspect and then remove at least one side of motion...

 

On the axles, but the coupling and connecting rods are plain (white metal) bearings I believe.

 

The coupling rod bushes and knuckle-joint pins had to be replaced on the 1954 tests due to wear. The report states that the original bushes were steel (which sounds unusual) and were replaced by bronze. The inside big end bearing also failed and a coupling rod bush had to be remetalled (presumably a replaced bush) but those problems were apparently due to the oil feeds.

 

Both sides were removed.

 

Is that on the motion, as well as axle boxes? Because I thought the coupling rods were plain bearings, but even if they were roller, it only takes a bit of grit, or a failed seal to very quickly render them useless, but here's hoping that it's a precaution rather than anything else and that Crewe soon have her repaired and back under test again.

 

I don’t know what the problem was but the coupling rods were removed and you can’t just remove one side, even if there nothing wrong with the other.

 

I guess the Middle Cylinder con rod stayed up..... That would have been a feat of F1 proportions to remove that in 2h20 without a pit..

 

Thrilled that 71000 is steaming again!general feeling

 

You could remove the connecting rods but leave the coupling rods. Removing the coupling rods from one side and not the other would be seriously unwise.
I do wonder why they apparently replaced the rods that drive the Caprotti gear after removing the coupling and connecting rods. Maybe reconnecting them to the cranks was easier than disconnecting the other ends.

You would need to be very careful to keep the loco in mid-gear with the gear being driven from the middle axle, the inside cylinder connected (I think?) to the front driving axle and the driving wheels uncoupled.

Edit: corrected a typo "than" to "that".

 

Probably easier than oiling up a Castle without a pit, Ian? Bold!

 

Is there any news on the Duke's issue? Seems a shame when she seemingly ran so well at the SVR, although I am suprised the opportunity wasn't taken to run her up to 50mph given how comprehensive the rebuild has been.

 

Seemed to do a lot less running in than previous LSL visitors

 

I would assume that it was either to keep the valve setting/timing as it was,(whether it was set up correctly or not,) or depending upon the disposition of the valves to prevent the (still connected?) middle piston from hitting/damaging the valves.

 

The pistons and valves are never in conflict, not like with an internal combustion engine where the valves open into the combustion chamber. Usually, the valves are held on their seats by steam pressure from the open regulator so drop off their seats when it is closed, allowing free movement of air between each side of the piston.

 

They normally have a minimum amount in mind, I should think it clocked up close to 500 miles overall, even with the shortened line.

 

So it would probably have been the first part of My post, preserving the 'Timing', I know from experience with Sentinels that 'Someone else' dismantling bits can cause inconvenience when re-assembling. As an aside since Duke of Gloucester has a camshaft drive on both sides is one for admission and the other exhaust?