Bulleid Pacifics - Past or Present

Its not the footage, but the furore from the armchair experts & reactionaries that exacerbates the situation..................

I watched the GCR footage, and just went oops, someones lost their job...................... as for this one with Tangers, utterly inconclusive - and I side with the reports from those that were there!

 

Also if that was a blowback there is no way that tour would of conutied that crew would of been hurt. Its just a werid affect you get with poor lighting and a low quality camera.... got to admit it looks impressive and I would dread to think the amount of damage that would of been done if that did actually happen.

 

I would have thought that blowbacks in the open air are pretty rare in any case (note that I'm not saying it doesn't happen). To be honest, this is an effect I've tried countless times to capture on camera, but have not been successful.

 

Where is the intermediate overhaul on 34046 likily to be done?

 

Incoming....Ok Bulleidophiles, just to chuck a plump and flightless pigeon amongst the Cats -
a Pacific combining the best features of original and rebuilt would feature/ look like ( Seconds out.) what. (ding-ding)...

 

Mechanically as per the rebuilts , but with the air smooved casing, no steam reverser or steam powered firehole doors. removable hinged access panels to access oil pots and sand boxes etc, simular to an A4 has

 

Why no steam powered fire hole doors? They are the best bit!

 

Apart from the aesthetics of the spam can shape, which must be a matter of taste, is there any feature of the original design that is superior to the rebuilt version? Does the enclosed valve gear actually save a significant amount of time oiling round? If so, how would you keep that benefit while overcoming all the disadvantages of that arrangement?

How about trying Bulleid's original plan using spur gears instead of the chains?

 

Yes the originals wheels had almost no hammer blow, due to the lack of counter weight.

 

Rebuilds were a fair bit heavier also, so less route availability. More of an issue for the intended 'light' pacifics, I'd imagine.

Can someone explain where this extra weight comes from? I'd have thought losing the air smoothed casing would have shed quite a bit

 

Even a significant weight difference between air smoothed casing and boiler flush casing is pretty small in the overall context , compared to say miniaturised valve gear versus full size with the counterweights to boot

 

The weight difference is actually quite small. For example, Bradley gives the following loco-only weight for a final series Merchant Navy:

35021
As built - 93 tons 18 cwt

35021 - 35030 series
As rebuilt - 96 tons 1cwt

That's little more than two tons variation, and is probably made up of the sum of lots of little detail variations - for example, the smokebox on a rebuilt was much more substantial; the rebuilds had balance weights; the steam reverser was removed but replaced by a shaft reverser; the air-smoothed casing was replaced with conventional casing, but handrails and smoke deflectors were added etc etc. On the WC/BB series, the extra weight was about 4 - 5 tons.

Worth noting that there was sufficient variation in design of the MNs (for example, and significantly, in boiler design and thickness of frames) that there was several tons variation in weight between early and late examples. (Standard Southern Railway conditions for weighing were to be in steam with a light fire and 3" of water in the glass).

I suspect, but don't know, that the restrictions on route availability of the rebuilt locos, especially west of Exeter, probably had more to do with increase hammer blow than increased axle load per se.

Tom

 

Jarvis's rebuilds replaced the troublesome parts of the design with conventional alternatives. I'd like to know what further development and refinement of the troublesome parts would have produced. So I'd like to replace the unreliable steam reverser with a different design. IIRC, the one used was a rather old Eastleigh design, but the Southern had another, more effective design available (from Ashford?) If this - or perhaps a further-improved version - were used instead, most of the running problems might have been solved. Likewise, improving the oil-bath with modern oil-seals and perhaps some "tweaks" to the detailed design would make that a more practical feature, and stop the boiler lagging from being soaked in oil and catching fire. I believe most footplatemen would want more, and more-easily controlled, dampers, as were fitted to the rebuilds. (I remember talking to an MHR fireman after his first few turns on Wadebridge who thought it a mistake to stick with the original damper arrangement when '007 was restored.)

 

Indeed I think i remember seeing somewhere on the 34007 website that the intention is to for the later modified design hopper ashpans to be fitted at the next overhaul.

 

It's on the News Page here; http://www.wadebridge34007.co.uk/ - Just go down to 26th May 2013.

 

As far as I am aware, oil leakage was more due to stress fracturing of the oil bath itself rather than the sealing arrangement of the casing, hence the desire to dispense with the oil bath completely, rather than just design and fit new seals, also the de-tuned version's hopper ashpan with damper doors was fitted to 34092 during its recent (25 years, is it really so long !) overhaul.

 

Heard that once the wartime quality seals on the steam reverses were expired and replaced they functioned quite well...
surely theres a heat resistant 'plastic' that you could make the oil bath out of these days ?

 

Interesting question. Where could she be accommodated for the work? Would she go back to Riley's? Probably not with all the work going on with 4472 plus moving the Loco works to another location.
Could she go back to the WSR? Possibly. Or could she go to Ropley? Perhaps. Crewe may be a possibility but there is a long queue of jobs currently at Crewe.