6880 Betton Grange

Morning everyone,

After 6880 failing with a suspected gasket problem in her smokebox, do we know if she's been repaired yet?.

Thank you .

 

6880 was in Minehead shed yesterday.

 

Thank you - I imagine then that her visit to the North Norfolk Railway might be delayed.

 

Latest news and photograph thanks to Josh Brinsford
''Repairs now completed and test runs due next day. No 6880 is expected back in revenue-earning service straight after successful testing''. <BJ>

 

That's excellent news .

 

Did anybody else think 6880 sounded a bit off it at the WSR? Something to do with the valves?

 

I've noticed that her exhaust bark has what appears to be a 'shriek'-like edge to it - it was like this at the Glos/Warks too.

 

Saw the engine on a low-loader going past the old Obridge pub in Taunton this afternoon. Most incongruous sight!

 

6880 to enter service on the North Norfolk Railway tomorrow (10th August) and is currently rostered until Sunday the 18th. Photo was taken on a test run yesterday.

 

Cracking shot!

 

* 10 to 18 August

 

(On the North Norfolk thread)

I hadn't noticed before, but at 1:15 in that video steam is coming out of three drain cocks. There would be one for each end of the cylinder, but why are there three?

 

Steam Chest - as well as cylinder ends?

 

I could be wrong, but given that the stroke on the Grange's cylinders (as with most 2 cylinder GW locos) is 30 inches (quite long for a British steam loco) it might just be a central drain cock on the cylinder to help aid drainage of excess water on what is quite a long cylinder, regardless of where the piston is within said cylinder.

I'm not sure why you would need a steam chest drain as the doesn't the steam chest naturally drain into the cylinders? Plus, there isn't a piston in the steam chest so you don't have the potential problem of a piston meeting non-compressible water that the drain cocks are designed to mitigate

 

Steam chest drain cocks. They are quite common on locos. Have a look at Black 5's, BR standards, Southern Schools and most GW locos, as examples. Even industrial locos can have them but they are often hidden underneath. (I was unblocking one at the weekend.)

 

With a slide valve loco it is more important to have a drain cock on the steam chest than on the cylinders. If there's water in the cylinders the slide valve will simply be forced off its seat and the water pushed into the steam chest. I know of several locos that don't have cylinder drain cocks but do have a steam chest drain cock. If you don't have a steam chest drain cock and the regulator is leaking by slightly the steam chest can get full of steam if the loco is in mid gear. Try moving the reverser in such an event. The valves will be pressed hard against their seats and it can make them almost impossible to move.

 

There is a considerable volume above and below the level of the valve sleeves between them in a GW cylinder piston valve block. Far better to drain this than expect it to work its way past piston valves & pistons. The large steam chest volume between the valve sleeves ensures a plentiful supply of steam at this important point in the circuit.

 

A reminder that 6880 is rostered for the final two days of the Festival on Rails at the NNR this weekend. There’s a West Country feel this weekend with 4277 and 53809 likely to be in action alongside the Grange.

 

The Battlefield Line have announced that 6880 will be their motive power for their Santa Specials and Mince Pie Specials this December, as well as participating in their Winter Warmer Gala in January 2025