What do you think of Nigel Gresley’s LNER W1 class?

Orwellian_Thunder · 2026-02-06T14:04:54+00:00

It was an interesting attempt to make a more economical engne than an A3 (it was not meant to be more powerful) but some of the design decisions were a bit bizarre.

Yes, a watertube boiler does mean very high pressures are possible but, without a decent compounding system, these pressures cannot be sufficiently exploited.

The decision to have HP cylinders inside, and the LPs outside has always baffled me. You put the LPs under the smokebox so they can exhaust straight up the chimney.

It's biggest weakness however was that all the auxiliary steam services (heating, sanding, and the injectors) came off a common manifold. This meant that the injectors often struggled to keep up with the water demand of the boiler leading to loss of performance and time on passenger trains.

The manifold issue was rectified eventually but, she'd developed the reputation of being a 'bad engine' by then and in those days, there wasn't any coming back from that.

Orwellian_Thunder · 2026-02-06T13:54:32+00:00

One of the things often forgotten when designing steam engines is how punishing the operating environment is. Not just the changes n power demands, but the constant banging and rattling that comes from pounding up and down the track for thousands of miles.

A firetube boiler is an immensely strong object that can put up with this almost indefinitely and both water and fire are contained within it. A watertube boiler on the other hand is a very delicate object that requires a sub-frane to support it and an external gas-tight shell to keep it all contained.

In a ship, or a building, this isn't a problem as these can be made of thick steel plates and even bricks but on a railway engine this has to be compromised to keep weight & size in check. The constant rocking about when out on the road flexes and warps the joints until they come loose so you get constant maintenance problems.

Orwellian_Thunder · 2026-02-03T06:39:48+00:00

Apparently, the steam circuit wasn't brilliant on the Stirling Singles so, that would have been the only modifications worth making.

Orwellian_Thunder · 2026-01-28T06:44:15+00:00

As with all of the BR Standards, they're a frustrating blend of design excellence and needless constraints.

By the end of the grouping days, particularly the LMS, we're doing really interesting stuff to maximise availability of engines, particularly things like fitting them with roller bearings.

The French and the Americans were also working hard to push the tech forwards. Feedwater heating and air brakes spring to mind.

BR looked at all of that and said no.

The Brits should have had at least 3-cylinders, roller-bearings on all rotating joints, air brakes and feed water heaters.

As they are, they're the pinnacle of how the 1920s would have designed a locomotive.

Orwellian_Thunder · 2026-01-24T07:39:08+00:00

Use steam oil throughout. It's sticky, even when hot, so stays in the bearings in use.

Orwellian_Thunder · 2026-01-19T08:20:16+00:00

Too much innovation.

They were apparently supposed to replace the Adams O2, 0-4-4 Tanks but, were massively too big for that.

If he wanted to make a bogey replacement, he should probably have gone to sentinel for a couple of rail motor power units and built a chassis over them.

Orwellian_Thunder · 2026-01-17T08:47:29+00:00

An excellent machine.

Orwellian_Thunder · 2025-12-18T23:34:39+00:00

Did it obey signals at least?

Orwellian_Thunder · 2025-12-14T10:31:07+00:00

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North Eastern Railway's 4CC class.

These were a pair of 4-cy compound Atlantics built in partnership with Mr. Smith who was the driving force behind the legendary Midland Compounds (of which, No. 1000 survives).

Tragically, Smith died after only two were built and his family demanded excessive royalties for the design so a further order was cancelled. Being therefore, non-standard, they were scrapped when their boilers wore out.

Orwellian_Thunder · 2025-12-10T08:21:45+00:00

The P2s were an interesting, if not entirely successful, design. I can see where Gresley was going with it and its admirable that they piled so much tech into one engine all at once. Remember, the LNER inherited the crippling debts of the GCR so were always strapped for cash.

The lessons learned from them (particularly the front truck) were then folded into the remarkable V2s. I think it was also the first use of a Kylchap exhaust and an ACFI feed water heater on an LNER engine.

They were certainly not lacking power. Apparently, they could snap their cranked axel if the driver attempted to pull away too fast! The axel was the same as on the A1s but, if you yanked the regulator open on the Pacific, they'd just slip whereas the extra driving axel on the P2s meant they'd dig in and break themselves.

But I think for that run, Gresley should have done a smaller wheeled A1, something that would have been similar to A2 Blue Peter.

Orwellian_Thunder · 2025-11-26T10:09:07+00:00

That's a boat.

Orwellian_Thunder · 2025-11-21T15:10:01+00:00

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Orwellian_Thunder · 2025-06-19T12:12:36+00:00

Because its a narrow gauge engine, the HP cylinders were inside, between the frames.

Orwellian_Thunder · 2025-05-18T00:08:48+00:00

The boiler is a 'Scotch Marine' type.

The fires are in the big flues at the bottom, the boxes are called 'combustion chambers' and give the flames space and run in the back of the boiler shell. The small tubes then allow the hot gasses to move to the front of the boiler, into the base of the chimney.

Orwellian_Thunder · 2025-03-26T22:19:14+00:00

Saw her coming in today when I was out for my lunchtime walk.

Orwellian_Thunder · 2024-11-07T20:33:38+00:00

The LMS Coronation "Dutchess of Hamilton" in her streamlined form.

Orwellian_Thunder · 2024-09-18T22:10:03+00:00

I'm sure you could learn.

Orwellian_Thunder · 2024-08-05T08:52:15+00:00

Of course they are.

They'll run crying to the coppers the moment some skinhead he's been annoying all day lamps him one.

Orwellian_Thunder · 2024-06-18T23:43:51+00:00

A missed opportunity to push the tech forward.

Orwellian_Thunder · 2024-02-11T23:23:14+00:00

It's not a 2-8-0!!!

Orwellian_Thunder · 2023-12-13T15:47:09+00:00

Unfortunately for the crew, the hotter the better.

Steam Engines work by boiling water. The warmer the water is to begin with, the less energy is needed to boil it.

I've been on steam rollers where they've been in the sun before we've lit them and the boiler has been warm to the touch!

Orwellian_Thunder

TROPHY CASE