What Ifs, and Locos that never were.

And so it is, but then an industrial shunter isn't necessarily about power. If you consider that a Y3, with one of those engines, can be geared for 15960 lb tractive effort, and this machine had four of those engines, working in industrial sidings with all the potential issues of curvature and axle load that go with them, perhaps it makes slightly more sense.

 

Why though did Bulleid have this obsession with two cabs? As far as I am aware tank loco's run perfectly well in either direction

 

Fair comment! Thank you.

 

Indeed 8126, Sentinel 9603 of 1956 was quite a remarkable and sophisticated locomotive. Effectively 2 of the 0-6-0 vertical boiler locos coupled back to back but with a single Woolnough boiler, this loco weighed in at over 90 tons and had a tractive effort of 52,000lbs. It was built at a time when Sentinel had significantly advanced their vertical boiler locomotive, but it all came to an abrupt end when Rolls Royce took over Sentinel and soon introduced their all conquering diesel locomotives. However, to give an indication of the sophistication of the latest steam locos from Sentinel, their chassis formed the basis of the new diesels and some of the 0-6-0 steamers were actually rebuilt into diesel powered machines. Of course, we know how successful the Sentinel/Rolls Royce diesel locomotives were to become.

9603 was built for for a specific job, working the heavy trains at the Dorman Long South Bank Coking Plant on Teeside. On test on the Shropshire & Montgomeryshire Light Railway, 9603 worked a train of 1,300 tons. As mentioned up-thread, it was a popular and successful machine at South Bank and even after the complete replacement of the rest of the steam fleet by diesel locos - mostly Sentinels - at Dorman Long's works on Teeside, it was still on top of the job it was designed for. However, being the odd-one out, it was withdrawn in 1963 and finally scrapped in 1966.


Sentinel 9603 on trial on the Shropshire & Montgomeryshire Light Railway in 1957.

Cheers,

Alan

 

Is there a good book on Sentinel locomotives as that one is absolutely fascinating and almost entirely unknown

 

The chronicling of Sentinel loco's is quite involved, starting out with Kirl Willians rebuilding a Manning Wardle shunter using the engine and boiler from a 'Standard' Sentinel waggon, which was OK as a shunter, but suffered from having only I reverse position (75%). Willians was later employed at the Sentinel, in the rail dept. The first Sentinel made loco's had a modified version of the 'Super' Sentinel Waggon engine, with cams giving 2 reverse positions. Later loco's were available with variations of the DG (2 speed) Waggon engines and later railcars had a 6 cylinder single acting engine with shaft drive which owned a lot to the design of the S type (shaft drive) Waggons. Abner Doble had very little to do with production loco's, I'm fairly sure that the only 'Full Doble' (for want of a better expression) ie oil fired Monotube steam generator, piston valve compound cylinders and condensing was a shunter for the LMS, there was a semi Doble railcar built for the Southern, which worked the Devils Dyke branch, but there seemed a big stumbling block in the somewhat strained relationship between Sentinel and Doble in that being a Texan Doble had no problem with using oil firing, but for Sentinel not burning coal was almost an anathema. The Sentinel railcar at Quainton Road has the single acting S type 'inspired' 6 cylinder engine and a Woolnough water tube boiler, and therefore has very little, if any Doble input. The 6 cylinder Sentinel shunters have effectively 3 twin cylinder double acting engines based on either the Super or DG waggon engines.

 

Yes, this Sentinel locomotive is very interesting. I first became aware that it once existed way back in about 1970 when I purchased a copy of Industrial Steam Album and was blown away by the photo of the loco in the album - what a machine!! I heard or saw very little about it for over 40 years until a superbly detailed article written by John M. Hutchings was published in Industrial Railway Record No. 168 chronicling the development and demise of the Dorman Long Sentinels; the info for my earlier post came from this article. For me, there were further revelations as the article detailed the short history of the 6 Sentinel "Receiver" locomotives built for Dorman Long, another absolutely fascinating tale of an excellent steam concept nipped in the bud by the encroaching diesels.

If you want to obtain a copy of Industrial Railway Record No. 168, go to this page on the Industrial Railway Website:

http://www.irsociety.co.uk/books/record.htm

Scroll down to find Bob Darvills contact details to obtain a copy. There is a postscript to the article in Record No.175 that is worth having and an article on the testing of Sentinels on the S & M, again written by John M. Hutchings is in Record No.175. I think that you will not be disappointed if you obtain them.

Cheers,

Alan

 

As an aside , Kirl Willans was a friend , or relation , of Tom Rolt.

 

Whats the thermal efficiency of a Sentinel like compared with a conventional loco?

 

Yes, I'm fairly certain that he was Tom Rolt's Uncle, I'll have a read of the books later today, my last post was 'off the top of my head' and I've got a feeling that I misspelt his name as well.

 

Right, I've had a look at the book, KYRLE Willans was Tom rolt's uncle, the first Manning wardle conversion was named 'Ancoats' and belonged to Isham Ironstone Co. The work was probably carried out at Blackwells Engineering, where Ancoats had gone for a rebuild.
'Ancoats laid derelict at Ishams Quarry until the late 1950's.

The only 'Full Doble' loco was works number 8805 of 1933 for the LMS carrying the number 7192 which was withdrawn in 1944.

In may 1934 Sentinel built 3 06 60 (CO CO?) locomotives for Columbia with Doble engines but coal fired Woolnough boilers

The Devils Dyke branch railcar was Doble engined but had a S type waggon boiler with auto stoker and water level device lifting at 325 psi.

They also built some tender engines for Egypt in co-operation with North British which appear to have been outside framed 0-4-2's with locomotive boilers and a Doble engine on each driving axle.

The book(s) which I had a look at are The Sentinal Volume 1 by W. Hughes & J.Thomas & Volume 2 by J.Thomas and A.Thomas

 

an interesting locomotive and one most who have little people will know as Gator in the Thomas The Tank Engine TV show. It always surprises me that they chose this obscure locomotive to feature as I had never been aware of it until watching with my 3 year old! Http://ttte.wikia.com/wiki/Gator

 

These ones: http://www.douglas-self.com/MUSEUM/LOCOLOCO/egypt/egypt.htm ?

 

Yes that's them, great article, the engines are effectively giant Doble car engines, but running at much lower pressure (and superheat) than Doble intended, I can't help but think that oversized Super Sentinel poppet valved engines would have been better.

 

I wonder if Bulleid was aware of these? A Leader with one or two of these motors on each power bogie would have met his criteria for a fully enclosed engine. To provide room for the Sentinel engines the centre axle could perhaps have been dropped and weight would have been further reduced by shedding the ungainly coupling chains. With higher boiler pressure to lift the power output to 250hp per motor, four would have given 1000HP and would surely have been enough to give the M7s on Waterloo ECS workings a run for their money!

 

Not very long ago (may even have been on this thread!) I recall looking at the chronology of the Dyke branch sentinel in relation to Bulleid's tenure on the ST, and I came to the conclusion that not only was it extremely unlikely he ever saw it run, but he also probably had next to no opportunity to study it mechanically while static before it was stripped of its interesting components. At best, he may have had the opportunity to study whatever technical reports were prepared, but in the middle of a very hectic workload.

Edit: see here:

https://www.national-preservation.com/threads/what-if.715873/page-8#post-1533067

Tom

 

I'm sure that Bulleid would have been well aware of the Sentinel technologies from his time on the LNER. After all, they had more of both locomotives and railcars than any of the others. Even if the LNER ones didn't use the latest Sentinel technologies, I'm sure that their salesmen would have kept them well aware of developments.

 

here is Bulleid standing next to one of the Colombian Sentinels whilst on test in Belgium - along with Hawksworth, Gresley, Stanier...