Hi, this Ammonia train in the fifties was often doubleheaded over the Wharfedale line through Ilkley. It was usual to see a LNE J39 or two or B16, WD 2-8-0 sometimes combinations of all and eastbound, sometimes a Skipton LMS 4F, 8F or other exLMS engine would be helping the struggling LNE one, it was built a joint MR/NER line afterall.
The oil train refered to in some posts in this period was composed of the old 10,12 ton unfitted tanks like the ones Bachmann did recently in a three pack marked Shell/BP, again mostly doubleheaded with the same combinations as the Ammonia trains.
The Ammonia tanks at this time were the wartime built tanks similar to the old white liveried Hornby Dublo Chlorine tanks we all remember but were a larger diameter tank on the same chassis, these unfitted tanks lasted into the sixties in the WD, MOS and ICI liveries mixed together ad-hock. The photo shows the later vacuum fitted tanks but there are still photos of these tanks doubleheaded by steam.
To be fair though the doubleheading on these unfitted trains was as much to help the braking as assisting the train engine, forty full oil tanks took a lot of stopping.....
How do I know all this? ..... I'm modeling the line and have been building up the stock for it. 35 oil tanks of various types and WDs to haul them. The Ammonia train will be 14 scratchbuilt tanks plus barrier wagons which was around the limit for a J39 so sometimes it might be doubleheaded with anything as mentioned above.
Interesting discussion.
Dave Frk.