This week saw the first of the new Hornby ‘Original’ Merchant Navy Pacifics hitting the retailers, see my Talking Stock #35 post here for more details and also the full size ‘Rebuilt’ Merchant Navy Pacific 35006 Peninsular & Oriental S. N. Co. steaming in public service for the first time in 2017 on the Gloucestershire and Warwickshire Railway (GWSR) for the week of services allied with the Cheltenham Races Festival. With this in mind I thought it was time that firstly I finished my model of 35006 in her as preserved guise (being a shareholder), and also that I mentioned the Rebuilt Merchant Navy Pacifics on this blog, although they are of course out of my usual 1946-49 modelling period.
Rebuilding the Merchant Navy’s
Although in general the Merchant Navy class as introduced were a success, proving to be powerful and very free steaming, one of the outcomes of the less than scientifically carried out Locomotive Exchange trails in 1948 and further performance and efficiency tests carried out at the Rugby Stationary Test Plant between March 1952 and January 1952, showed them to be costing a lot in: coal, water, oil and secondly maintenance when compared to other classes. These costs along with issues of leakage of oil from the enclosed motion oil baths and the reliability and accuracy of the steam reverser / cut off setting led to the Southern Region looking at options to improve the engines. The option chosen as opposed to trying to overcome the individual issues was to rebuild the engines with more ‘standard parts’.
The task was given, in 1954, to R.G. Jarvis of the Chief Mechanical and Electrical Engineer’s Department at Brighton, his new design replaced the encased oil bath and chain driven valve gear with three sets of more traditional Walschaerts valve gear, new style piston heads and rods, regulator and a screw-link type reverser. The ashpan and grate were also replaced and included hopper bottom doors and front and rear dampers. A new fabricated smokebox, superheater header and steam pipes were also fitted.
The frames, outside cylinders, boilers were retained along with the: Bullied-Firth-Brown wheels (although now needing balance weights to be fitted), axleboxes, the efficient ‘clasp’ locomotive brakes and the ‘Stones’ steam generator for electric lighting both for the engine headsignals and in cab lighting. The same tenders were utilised, albeit with the side raves cut down to ease water filling access and reverse running view. The drawbar between the loco and tender however was replaced.
Externally the ‘Air Smoothed’ casing was removed giving the look common to the recently introduced BR standard classes, although the characteristic oval shaped smokebox door was kept. Sanding, from replacement sandboxes, was also added to the leading driving axle, whilst rearward application was incorporated to the middle driving axle and new mechanical lubricators were accessibly mounted on the running plate alongside the boiler.
In 1955 the British Railways Board gave authority for fifteen of the class to be modified and authority for rebuilding the remainder swiftly followed. In February 1956 Eastleigh works released 35018 British India Line in its newly modified form (35018 as the prototype rebuild remained unique to the rest of the class as the front sandbox filler position and injector pipework differed), by October 1959 all the class had been rebuilt.
Performance of the rebuilt engines was indeed successful, solving most of the maintenance issues, although one drawback was that they put greater loads on the track, than the largely self balanced originals, as a result of increased hammerblow, caused by the balance weights required for the Walschaerts valve gear.
My model of rebuilt 35006 as preserved
The release by Hornby in the year 2000 of the rebuilt Merchant Navy locomotive heralded a new generation of model steam locomotives by Hornby and was a step change of standard of models reactive to competition in the market place and gave us a new super detail standard featuring blackened finish handrails and wheels with etched brass valve gear, detailed cab interior, and a five pole motor housed and driving within the locomotive itself. Over the years a number of the class have been released with a few modifications to the tooling along the way, although as yet none of the first series engines as rebuilt have been released as the 5000 gallon style tenders they were paired with have not been tooled.
As 35006 in preservation has been paired to a brand new built larger 5100 style tender I have used a Hornby R1038 35012 United States Lines (split from a train pack) locomotive as the basis for my model.
Firstly I removed the cabside number numbers via my usual method of soaking the Hornby printing in enamel thinners and rubbing off with a cotton bud and replacing with HMRS Pressfix decals.
New nameplates and smokebox door number plates were fitted along with an extched 72B Salisbury shedcode plate on the smokebox in the slightly higher position than usual, level with the lower smokebox hinge, on 35006 which was a charactoristic of her when in service. All the plates were obtained from Fox Transfers.
I replaced the front steps as supplied by Hornby by the more robust lost wax cast versions, along with a set of the cylinder drain pipes to complete the front end look, obtained through RT Models, from his excellent Albert Goodall range.
As I am modelling 35006 in her preserved condition I want to to also represent her superb external paintwork finish with a reflective and classic oily rag polished hue and have therefore given the model a coat of Kleer floor polish to give a such a finish to the paintwork (and also seal in the decals).
More details of 35006 and the locomotive Society can be found on my dedicated page here. Also it is worth mentioning the 35011 The General Steam Navigation Locomotive Restoration Society that was formed last year with the intention of not only restoring 35011 back to working order but doing so back in original air smoothed condition condition complete with Bulleid’s oil bath encased valve gear incorporating chain drive elements to fill the gap in preserved examples left by the entire class having been rebuilt.
3 thoughts on “Talking Stock #36 The rebuilding of the Bulleid Merchant Navy Class and a touch of Workbench Witterings”
Just a gentle correction – 35018 was released in February 1956 not 1955 (I’m sure that was just a typing error as I know you know it was 1956). Also, the mention of the 35011 project – will this be the first (and only) Unrebuilt Bulleid Pacific?!
Hi Jeremy yes well spotted, it was indeed a typo now duly corrected
Thanks for spotting and letting me know much appreciated