After looking at many pictures of this wonderfully designed engine, it became apparent that many changes took place to its original design from the first batch, introduced in 1889, and the last batch that came into service in 1927. There were a total of 34 B-Class engines built and used on the Darjeeling Himalayan Railway.
The first batch came out with no wheel bell crank balance weights or out slung cylinders , however if you look very closely at the second introduced 'B' class engine from 1889 today, at the Delhi rail Museum, it is totally different to its original form. This indicates that over the many years of service many mechanical changes took place to this design, some from new and some from the well known Tindharia rail workshops. Also Tindharia produced three new engines from spare parts from UK. After a visit to the DHR railway and Delhi Rail Museum in 2010 it was obvious that many original engines did not exist in their original form. I only found one engine with its builders plate on and that was number 777, in the Delhi Museum. Most engines had interchanged parts. With this in mind I took the stance that I would use copies of the original Sharp Stewart and Baldwin plans, plus the large amounts of information and photographs from all three of Terry Martin's wonderfully illustrated books on the DHR to identify what to build.
Even the plans did not indicate the later changes that the Tindharia workshops made over the many years that they serviced and overhauled most of the DHR engines.
In the end I decided on the one course of action and that was to build the only engine I found with all the makers and other plates attached, including the one from Tindharia workshops noting a major rebuild in 1917. This would have included an extension to the smoke box (all engines had this modification), wheel balance weights fitted and possibly the out slung cylinders as we see them to day. So I picked out number 777 in the period just after it was taken over in 1952 by the North East Frontier Railway (part of Indian National Railways). This period was one of the times when engines seemed reasonably well looked after. The driver and two firemen's names being painted in yellow English alphabet lettering on the left side of the coal bunker. The letters 'N' and 'E' were also painted on the left side of the coal bunker and Hindi on the right side . Later times saw the original numbers painted on the coal bunker sides disappear in place of the Indian Railway plates as you can see them to day.
There are plenty of pitfalls in building this engine and now that we have most of the work completed Mike is set to come to New Zealand in December to drive this engine and complete the design work for his Cad drawing programme. I hope to have it in steam early November.