35018 British India Line

It belongs at 10A and it had better come back to 10A or we will assemble our troops (and whippets) and we will fetch it back home.

 

It might be owned by 10A, but B I L should be given a chance on the routes she was built for. Do I detect a bit of jealously for Eastleigh, Brighton and Ashford built locos?

Just make certain that the whippets don't scent mark the 3rd rail!

Cheers, Neil

 

Smoking Whippets Actually Neil, its more that an MN is superior to any LMS stuff, they can't afford to spare her.

 

Never superior to LMS stuff. it's just that there's a shortage of the latter (and LNER for that matter) and we have to make do with an MN, otherwise we might end up with a load of brass and copper, instead.

 

You may well be right in historical terms but as there are proportionately more MNs surviving and of all 8Ps they are best suited to today's demands, arguably they deserve to attract greater resources from those with an interest.

 

That makes sense. It's to be hoped the current shortage of main-line 8Ps will be alleviated before too long, but one or two more MNs would help. They seem to be more gauge-friendly than most, and their slightly smaller wheels than most 8Ps didn't prevent 100 mph occasionally and are of no consequence with a 75 mph limit. Their somewhat lower TE, however, can make starting more difficult when only one cylinder has steam: I think this happened both with last year's Bournemouth Belle starting from Waterloo and a few days later with the Waterloo Sunset's eastbound start from Sherborne.

 

The TE isn't an issue in that scenario as it would be common to other 3 cyl 8Ps of the LNER variety too which have larger driving wheels, A2 excepted. A MN should in fact have a slight advantage with the smaller driving wheels starting trains.
Anyhow, if I had a vested interest in fleet sustainability, the resources and infrastructure my money would be ploughing into MN acquisition / restoration.

 

But, the nominal TE for a given loco class is what it is, and driving wheel diameter is accounted for in the calculation. If two locos have similar nominal TE the driving wheel diameter is irrelevant.

Dave

 

Common to the LNER 3 cylinder locos, yes, but not to the Stanier Pacifics or the Kings; the latter however having it seems progressively worse gauging issues.
As Smokestack Lightning says, driving wheel diameter is accounted for in the calculation of TE, and the Bulleids do have significantly lower TE than other locos of similar size: even before the boiler pressure reduction from 280 psi they were a bit lower.

 

Thanks for the kind comments about the performance of MN class locos.
If proof is needed, have a quick look at the comments for 3rd June to Kingswear and todays trip to the far west.
Or indeed the reports of 35018 on her first trip over Shap and the S&C.
By the way, 35028's driving wheels were turned down to 6'1" on the last overhaul so that should aid the TE available.

Cheers, Neil

 

Starting effort is aided by smaller wheels regardless of TE. A V2 would start the same load on the same track more readily than an A4 at same boiler pressure and cut off, because the V2 is effectively "lower geared" due to the wheel diameter being 6" less.
I assume this principle influenced Bulleid and later 71000s designers as an acceptable compromise to efficiency of high speed running.
TE is only real world relevant to games of Top Trumps.

 

True up to a point. But if two locos have the same TE then the one with bigger wheels will, in effect, have a bigger engine.
(Higher boiler pressure, larger cylinder bore, longer stroke, more cylinders or a combination of the above).

Dave

 

Well my point was in response to the suggestion MNs have more difficulty starting trains than "more powerful" contemporaries. The on paper TE is of little real world value when there is an unequal struggle with the railhead to apply the greater notional power.

 

Is there any evidence that a MN has more difficulty starting a train than any other comparable loco? The modern-day performance of "Clan Line" on the very heavy VSOE trains round a hilly, awkward Surrey Hills circuit would suggest no particular problems on that score. I can't help thinking that the supposed poor performance of Bulleid pacifics on hills is more enthusiast myth than anything else.

Tom

 

Totally agree Tom, as I've said upthread objectively for the modern era MNs are as close to an optimum 8P as you can get without bulding something else from scratch to a new design.

 

What engines does West Coast have available for its tours and those it operates , 2 jubilees, a 8f and BIL, that it controls, or owns I am wondering with the regular loadings being in the region of 10-12 coaches, I wonder if Bodmin's restoration has been started yet as to have both 46115 and 34016 available would certainly ease the situation in the next few years, as both are gauge friendly 7p rated .

 

No it's not. The only advantage a V2 would have over an A4 is the 23 tons less weight it had to drag around.

 

Clan Line, about 650 tons, from a standing start up a 1-in-96. Listen to her accelerate!

(NatPres formatting has removed the timestamp for some irritating reason - it's 3:14 that you need to skip to)

 

A smaller wheel has reduced radius which means revolution takes less time and surely therefore the next piston stroke begins sooner to provide the tractive force in order to get the load moving? That seems to me a mechanical advantage of the smaller wheel, all other things being equal.