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The Worst Diesel Locos in the World? - Pt. 1 Concept and Body



It is fair to say that the North British Locomotive Company's attempt to move into the brave new world of modern traction was an ignominious failure. After six decades as one of the leading locomotive builders in Britain it attempted to enter the diesel era via a licencing deal with MAN of Germany; but the results of this push can be classified into two groups - failures and complete failures. NBL folded in April 1962 under the resultant weight of warranty claims and lack of new orders, its financial position being made even worse by a commercial policy of selling the Pilot Scheme batches at a loss to buy its place in the new diesel era.


Which of NBL's four classes of diesels - TOPS classes 16, 21, 22, and 41 - was worst is debatable. A sufficient commentary on them is that 3 of the classes were eliminated immediately by the National Traction Plan in 1968, and the Class 22 "Baby Warships" succumbed in 1971. Since the latter were still in original form and were further doomed by being hydraulics, they were arguably the best of the very bad bunch.


20 of the Class 21s were rebuilt with new more powerful Paxman engines in the mid 1960s and became Class 29 , but even that was not enough to save them , and all the rebuilds had gone by the end of 1971


Of NBL's British diesel designs only classes 21 and 22 proceeded beyond a pilot batch. 58 Type 2 NBL diesel-electric lemons (designated Class 21 under TOPS) were built between 1958 and 1960, but as early as March 1960 most of the ER allocation was reported as being stored unserviceable at Peterborough. The entire class was banished to Scotland a month later, on the theory that it would be quicker and easier to send them back to NBL under warranty from a Glasgow shed (although there was speculation that the move was in fact an attempt by the BTC to hide the debacle from the London-based national press); but NBL's collapse two years later put an end to that idea. Class 21 locomotives were being stored unserviceable as early as 1964; and some of them may never have turned a wheel again, being sent directly to the scrapyard from store. It seems to have been ScR practice to send them out on trains double-headed in the hope that at least one of the locomotives would still be working when they finished their diagrammed day's work.


It is therefore arguable that Class 21 constitutes the worst design of diesel locomotive ever to go into volume production. Bad as the Type 1 locos of Class 16 were, there were only 10 of them, and they lived out their short lives at Stratford. Some of the Class 21s may have had service lives of as little as 4 years before they were stored; and there is no parallel to their mass withdrawal and exile to Scotland in 1960


I've always been intrigued by these locos ever since Hornby introduced their "Class 29" in the late 1970s. This was a strikingly ugly loco, and a fascinatingly obscure one; when Ravenser Mk1 was struggling to find a small mainline diesel that would work, one turned up in my local modelshop second hand for not much money and I promptly bought it. I later detailed and repainted it as a Class 29, and getting the thing converted to DCC is now high on the agenda. (The back story being that RTC Derby claimed one of the last locos in traffic to replace the Baby Deltic, so it survived to c1980 as an RTC loco)


At some point I also acquired a second battered body for £2, followed by a chassis frame and Hornby power bogie. The latter items went to my Baby Deltic project - but with that complete the possibility of a second compact Type 2 for Blacklade's illicit "steam period" began to stir in my mind.


The "funny trains" period on Blacklade is nominally set c1958. We may imagine that an NBL Type 2 has been sent to BR's principal diesel-loco building works for evaluation trials to find out what is wrong with the thing. These trials can quite plausibly bring it to Blacklade on short trains. (Since Blacklade and Hallamshire replace Derby and Derbyshire , Derby Works doesn't exist under this scheme of things, and the MR's locomotive works is now at Toton. As there is a regular Nottingham/Blacklade service, the appearance of an NBL Type 2 hauling two Midland suburban coaches is perfectly plausible.)


Dapol are bringing out a new high-spec 21/29 any year now. When it finally appears it will cost at least £150 - and I don't want a Class 21 that much. So this is an exercise in a fun loco on the cheap.


For a power plant, I bought a second hand Hornby Class 25 at Warley. This will provide a 5 pole all-wheel pickup Ringfield motor bogie , and the Hornby body can be donated to a "high-spec 25/1" project


I have a Class 29 chassis frame and weight from Peter's Spares and a pair of Class 29 trailing bogies - the second will donate a bogie frame to the motor bogie.


Detailing bits come mostly from the scrap box - an A1 Models roof fan etch, another A1 pack giving cab-end detailing etches. These are supplemented by some very nice etched nickel-silver etches for cab windows from Shawplan. (A tip from C.A.T.Ford on the DOGA stand at Warley)


Progress to date is shown here:




The biggest problems with the Hornby model are in the cab front. They modelled a weird arrangement, with a Class 29 headcode box overlying nose doors - I can only believe that someone was working off an NBL drawing amended to show revised arrangements. For a Class 21 the headcode box must go - A1 provided a replacement etched nose door and etched discs.


And the transformation provided by the Shawplan etch for NBL cab windows is dramatic . I have deliberately photographed the end where I haven't finished filing out one window so you can see what I've done. Getting these in place with superglue - and making sure they stay in place during filing - is a little awkward.


One buffer head was missing - I've fitted replacement turned brass buffer heads from an A1 Models buffer beam detailing pack. I really had no other obvious use for these.


This is about as far as I am taking the bodyshell . I know someone did an extensive conversion building up the nose and reprofiling it. I'm not really sure what was involved and I'm keeping it simple and leaving the basic shell as it is.


Hornby modelled the original form of the main radiator grills - rapidly replaced by a squarish grill .I do have a set of replacement A1 Models etched grills, but as I am modelling a Pilot Scheme batch loco in 1959, I shall be leaving these grills alone.


As an original condition ER loco, livery would have been plain green - which is easy enough to do with a spray can.


The Baby Deltic proved to stall in some places on the layout - no doubt due to its deep flanges fouling lumps of ballast or chairs on code 70 bullhead. I've managed to remove projecting bits of ballast in several places , which has resulted in a partial cure. But (as noted elsewhere) I've developed a further fix - replace the chunky Hornby wheels in the trailing bogie with Bachmann coach wheels with their pin-points sawn off with a piercing saw. I still have to give the Baby Deltic a test run to see how much of an improvement this gives, but the theory is that if only one end of the loco is vulnerable to grounding then there should always be a supply of power to avoid stalling.


(I also suspect that - as with other defects - once the underlying issue is found by a vulnerable loco and tackled I'll see better running from other items of stock , which were just about coping with it)


The NBL Type 2 will be fitted with Bachmann wheels on the trailing bogie, and I bought a substantial DCC stay-alive along with a suitable decoder at Warley - I'm hoping this will result in a smooth-running and reliable loco.


I'm aware the Hornby model sits too high. But as I can't see any obvious easy way to fix this , I'm intending to leave this issue alone


I'm very pleased with the relatively quick and painless progress made to date. This should be a distinct cut above the 29 I detailed nearly twenty years ago

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The class 21s have always been a personal favourite, I don't know why as I never saw them in service.

I think it is because they are so unloved, and therefore relatively rare in photos.

Also, although ugly, they definitely have character.


I have a Worsley Works etch to base a 2mm model on at some point when I've cleared my workbench.


I'm looking forward to seeing yours come together

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I did something similar with one of these some years ago. It seemed to me to scrub up rather well. I didn't add the extra depth to the nose to which you refer, having seen other folks models I do understand the issue, but for mine on its own I don't really notice. Power is two Hornby Ringfields, the second one just clips into the Hornby chassis frame. With some extra weight the haulage is excellent.


You've made a better job than me around the windows, as I didn't file out the excess plastic. I did mine as an East Anglia variant which required changing the bodyside grilles, I do however have another in a cupboard somewhere, destined to be one of the first ten as you have done. A good saving on the likely cost of the new Dapol one!


Best wishes,



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