English Electric Type 1 and Type 2 prototypes

[RLBH]

Looking down the specifications of the English Electric Type 1 (Class 20) and Type 2 (Class 23), it seems to me that the two are practically identical in terms of traction characteristics, with about the only difference being the addition of a steam heat boiler on the Type 2. Meanwhile, the Type 1 is considerably more powerful than its' competitors from other manufacturers. To me, this suggests that the choice of prime movers was a little adrift.

With a 6-cylinder engine - the 6SRKT fitted to several export locomotives - the Type 1 would have had 750hp on board for a little under 600hp at the rail, equivalent to the BTH and NBL competitors and presumably lighter and cheaper to run as a result.

Putting the 8SVT into the Type 2 would probably have meant a slightly heavier design than the Baby Deltic, though perhaps not too much so given the extra structure put in to offset the lightweight prime mover. Traction characteristics would be more or less unchanged, and you'd wind up with a locomotive of more conventional design and presumably higher reliability.

This seems like a more sensible course of action, at least from English Electric's point of view.

I can see the point of trying the Deltic out in a mixed traffic locomotive, which partially justifies the choice as an experiment. The grossly overpowered Type 1 prototype, which was basically a Type 2 powertrain dressed like a trip freight locomotive, I find harder to explain. Does anyone know what the logic was?

 

[Taunton]

Class 20s, after the first few years, were run almost exclusively in nose-to-nose pairs, which gave a 2,000hp, eight driven axle, light axle load two-unit locomotive which worked very well in low speed slugging conditions. It will start a bigger train than a Type 4, just not get it going very fast. The fact that all the other Type 1 designs fell rapidly by the wayside while the Class 20 was reordered almost to the end of modernisation plan diesel production is a bit of a pointer.

 

[Shaw S Hunter]

I'm not sure the word logic really belongs in a discussion about Modernisation Plan diesels! The only explanation I can see is that, for whatever reason, EE decided that for domestic use mainline locomotives needed to have a V series engine rather than a K, perhaps arising from concerns about fitting all the other necessary equipment within this country's loading gauge. Given that the various D10xxx locos had been built with 16SVT units it was therefore an obvious move to produce V units with fewer cylinders to meet the Type 1 specification. In the event the V series engines proved to be very reliable in all their various forms, not withstanding the over complicated ancilliaries fitted to the Class 50, so it was no surprise BR kept ordering them. As Taunton has pointed out a pair of Class 20s made for a very useful low-axle weight articulated Type 4!

 

[RLBH]

The only explanation I can see is that, for whatever reason, EE decided that for domestic use mainline locomotives needed to have a V series engine rather than a K, perhaps arising from concerns about fitting all the other necessary equipment within this country's loading gauge.

I'm not entirely sold on this logic, partly because as an inline engine the K series engine would be narrower than the V engines, so less concern about loading gauge - and after all, the 4SRKT was successfully used on the Southern Region DEMUs, and the 6KT will probably still be driving Class 08s around depots when the last Class 800 is just a memory. But, institutional inertia is a powerful thing, whether on the part of EE or BR.

There is a consideration, I suspect, that the longer block of a 6SRKT might drive a longer locomotive than an 8SVT, which would be undesirable. But I'm still running up against the 6KT in the Class 08 here, and certainly export locomotives got 6SRKTs in a reasonable length in the right timeframe.

Certainly a pair of Class 20s made a useful alternative to a Class 40, but really that proves the point about them really being a Type 2 power package - the London Midland region planned on using pairs of Type 2s on Type 4 duties right from the start after all! In any case, a decent chunk of the Class 20s were certainly ordered for Type 1 duties, and the final batch was to replace the failed Class 17; that the entire Type 1 requirement turned out to have been misguided doesn't change the fact that they were a really odd way of meeting it.

 

[etr221]

The more intriguing of the pair is the Class 23 Type 2 'baby deltic', which had a higher rated engine than the class 55 Deltics (2/3 the power from half the cylinders) - for a single engineed version of the Deltic using the same engine as the class 55 in a 1650hp Type 3 Bo-Bo would have seemed a more logical proposition - wonder if it was ever suggested?
I wonder if the class 23 was the result of a thought that EE ought to do a Type 2, or that there ought to be a small Deltic, rather any more serious consideration.

The other little mystery is that the 8CSVT engine in the class 20 was never uprated, as in the Portuguese 14xx class.

 

[RLBH]

The more intriguing of the pair is the Class 23 Type 2 'baby deltic', which had a higher rated engine than the class 55 Deltics (2/3 the power from half the cylinders) - for a single engineed version of the Deltic using the same engine as the class 55 in a 1650hp Type 3 Bo-Bo would have seemed a more logical proposition - wonder if it was ever suggested?

I believe it was, in both electric and hydraulic forms - along with a few Type 4s in various configurations.

The other little mystery is that the 8CSVT engine in the class 20 was never uprated, as in the Portuguese 14xx class.

This is what prompted me to start down this line of inquiry! The CP 1400 class shows what an evolved Class 20 could have been, but as a Type 1 it wasn't competing in that space, whilst EE's official Type 2 was - unusually for them - a bit of a failure.

 

[Shaw S Hunter]

I'm not entirely sold on this logic, partly because as an inline engine the K series engine would be narrower than the V engines, so less concern about loading gauge - and after all, the 4SRKT was successfully used on the Southern Region DEMUs, and the 6KT will probably still be driving Class 08s around depots when the last Class 800 is just a memory. But, institutional inertia is a powerful thing, whether on the part of EE or BR.

I can't say I'm really sold on it either! As I said there is little logic to be found around the Modernisation Plan era. Perhaps someone needs to contact Roger Ford aka Captain Deltic for some pointers.

 

[Taunton]

The Class 23 "Baby Deltic" engines were a Napier product, as were their larger cousins, and although all were assembled by Vulcan, also an English Electric offshoot, Napier had been a very separate division of English Electric ever since they were taken over about 15 years earlier, principally for their aircraft engines. There was not a lot of dialogue between the Napier (West London) and EE (Preston) diesel plants, both separated from the corporate HQ in London, and I suspect their sales teams approached BR individually.

 

[randyrippley]

The 20 and 23 were built for different purposes
The 20 was a pure freight loco, slow, low axle load with a decent tractive effort for its power. They used the highest rated engine they had which would run reliably in a single cab design: using a V or deltic engine would have required a full width body - and so two cabs. It was intended as a production design and was a natural evolution of several designs EE had sold for export.
The 23 was primarily intended as a lightweight commuter passenger loco: lightweight high revving two stroke engine giving a higher speed and decent acceleration for 3/4 coach trains. It was an experimental comparison with the unusual slow-speed two stroke of the Metro-Vick CoBo, and the 4-stroke of the other type 2 designs. But it was an experiment.
EE themselves had little faith in the Deltic engine design. Remember that the engineering teams at Vulcan and Hawthorn both refused to build DELTIC and it had to be lashed up in Preston. The 23 only existed because we had a production line building lightweight deltic engines for the navy, and BR were desperate to avoid paying royalties overseas to Sulzer, MAN and Maybach. They were prepared to try anything. So they took a batch of unwanted naval engines and got EE to lash up a body using standard components. As anticipated by EE, the engines broke - and on a Deltic a bust engine means an engine exchange. Impossible to get a head/crank/piston with the engine in-situ. Expensive.
Sanity rapidly prevailed and the baby deltics were binned, along with the equally stupid CoBo fleet.
What did it prove? Marine diesels don't work in locos.

 

[Helvellyn]

Of course the Class 20s were not meant to be the "standard" Type 1. 128 were ordered but then the Clayton Type 1 (Class 17) was meant to be the preferred type. That didn't quite work out hence a follow-on order for an additional Class 20s, deliveries of which started in 1966 - four years after the last of the first order had been delivered.

 

[36270k]

An intercooled version of the Class 20 engine ( 8CSVT producing 1350hp ) was used in Northern Ireland in the Hunslet 101 class.

 

[randyrippley]

An intercooled version of the Class 20 engine ( 8CSVT producing 1350hp ) was used in Northern Ireland in the Hunslet 101 class.

Presumably the extra size of the cooler group mandated a full-width body and twin cabs

 

[Warwick]

The 20 and 23 were built for different purposes
The 20 was a pure freight loco, slow, low axle load with a decent tractive effort for its power. They used the highest rated engine they had which would run reliably in a single cab design: using a V or deltic engine would have required a full width body - and so two cabs. It was intended as a production design and was a natural evolution of several designs EE had sold for export.
The 23 was primarily intended as a lightweight commuter passenger loco: lightweight high revving two stroke engine giving a higher speed and decent acceleration for 3/4 coach trains. It was an experimental comparison with the unusual slow-speed two stroke of the Metro-Vick CoBo, and the 4-stroke of the other type 2 designs. But it was an experiment.
EE themselves had little faith in the Deltic engine design. Remember that the engineering teams at Vulcan and Hawthorn both refused to build DELTIC and it had to be lashed up in Preston. The 23 only existed because we had a production line building lightweight deltic engines for the navy, and BR were desperate to avoid paying royalties overseas to Sulzer, MAN and Maybach. They were prepared to try anything. So they took a batch of unwanted naval engines and got EE to lash up a body using standard components. As anticipated by EE, the engines broke - and on a Deltic a bust engine means an engine exchange. Impossible to get a head/crank/piston with the engine in-situ. Expensive.
Sanity rapidly prevailed and the baby deltics were binned, along with the equally stupid CoBo fleet.
What did it prove? Marine diesels don't work in locos.

The funny thing is, is that eventually E.E.'s proposals for the modification of the T-9 Deltic engine was accepted and after they were re-engined with the "new improved" T-9 they went on to be remarkably reliable little engines. E.E. actually had a brand new engine in mind for them - the "U" series V-12 which E.E. proposed installing in the 23 rated at 1,550hp. It was also available in an uprated version at - I think - 1,800hp. The installation of an 18-25 Deltic was also proposed giving it 1,650hp. I believe that the resulting noooooo! to the latter from the boardroom at 222, Marylebone Road was heard in the Vulcan Works.
Of course if someone - lots of them - on the board weren't in denial at the lessening of wagonload freight all of those stupid type ones wouldn't have been built. But it put off a few firms from the inevitable going under at the time.
The teams at Hawthorn and Vulcan didn't refuse to build the prototype Deltic, E.E. were up to their ears in building locomotives for export. Preston had spare capacity.
The class 23 wasn't an experiment. It was one of three classes ordered under the diesel pilot scheme of 1955. The order was for ten class 40s, ten class 23s and twenty class 20s except of course they didn't have class numbers then. They were known as type C type B and type A respectively.
Facts and figures from, "The Deltic Locomotives Of British Rail" by Brian Webb 1982. ISBN 0 7153 8110 5

 

[RLBH]

I can't say I'm really sold on it either! As I said there is little logic to be found around the Modernisation Plan era. Perhaps someone needs to contact Roger Ford aka Captain Deltic for some pointers.

Ah, there's always some logic in these decisions, even if it's based on considerations that seem strange at a distance of 65 years.

They used the highest rated engine they had which would run reliably in a single cab design: using a V or deltic engine would have required a full width body - and so two cabs.

Except of course that the Class 20 did have a V8 engine and one cab.

The 23 was primarily intended as a lightweight commuter passenger loco: lightweight high revving two stroke engine giving a higher speed and decent acceleration for 3/4 coach trains. It was an experimental comparison with the unusual slow-speed two stroke of the Metro-Vick CoBo, and the 4-stroke of the other type 2 designs. But it was an experiment.

That does actually help shed a little light on the matter - the 21s and 22s also had high-speed diesels and relatively low performance compared to the rest of the Type 2s, and all were initially assigned to suburban work. In fact, the first ten Class 21s were even weedier than the Class 23s. In steam terms, the 21/22/23 would be classified as 3P4F - maybe even 2P in the case of the 21/22 - whilst the 24/26/28/30 could be classified 4P5F. On a similar basis, Classes 15/16/17 come out as 2Fs, whilst the Class 20 comes out as a 4F - quite clearly a different animal. And

The class 23 wasn't an experiment. It was one of three classes ordered under the diesel pilot scheme of 1955. The order was for ten class 40s, ten class 23s and twenty class 20s except of course they didn't have class numbers then. They were known as type C type B and type A respectively.

In fairness, all of the Pilot Scheme locomotives were meant to be for trials, with mass production following after a few years experience with the trial types. It's arguable whether this was a particularly good plan, but it does at least make sense of the weird locomotives ordered in small numbers.

Tellingly, when the Type 3s and the lightweight Type 4s came along in 1961-1962, the alternatives were the combinations of engine, transmission and builder that had been tried in the Pilot Scheme and actually worked as advertised without too many breakdowns. Admittedly this was also tried with the Class 17, and turned out not to be such a success.

 

[Taunton]

Tellingly, when the Type 3s and the lightweight Type 4s came along in 1961-1962, the alternatives were the combinations of engine, transmission and builder that had been tried in the Pilot Scheme and actually worked as advertised without too many breakdowns. Admittedly this was also tried with the Class 17, and turned out not to be such a success.

The Class 17 (Clayton D85xx centre cabs) was none of the above. It was an unknown engine from a previously unknown builder, ordered in full production quantity straight from the drawing board. And they were one of the most unreliable of all. The BRB eventually corralled them all up well away from 222 Marylebone Road, in Scotland for the balance of their very short lives. Poor old Scottish Region.

I wonder what the aversion was to having a Type 1 with the normal arrangement of a cab at each end. There was every alternative conbination, none well received.

BRCW always seemed to produce products which were successful and had a long life. Classes 26, 27, 33, 81, even the dmus, outlasted most of their contemporaries and were well received. So I have always thought it was rather underhand that when the two later prototypes (Lion and Falcon) were offered, BRCW came up with the big Sulzer Co-Co, while Brush did the rather bizarre twin high speed engines one but with electric transmission. When full Class 47 production was ordered, it was Brush that got the business - but with the BRCW design.

 

[RLBH]

It was an unknown engine from a previously unknown builder, ordered in full production quantity straight from the drawing board.

It was tried in the sense that they claimed to have learnt lessons from the Pilot Scheme and ordered on the strength of that experience. Except that they did none of the above, as you say. Mysteriously, they got a lot better when they were built by Beyer-Peacock with Crompton-Parkinson electrics. Apparently the pair with Rolls-Royce engines worked better than the rest of the Clayton production run as well. If all of that had been done from the start then BR might not have needed to buy a second batch of locomotives for the disappearing trip freight market.

There was every alternative conbination, none well received.

Given the London Midland region's enthusiasm for multiple working of small locomotives, I'm almost surprised they didn't try a cabless version of one of the Type 1s purely to work in multiple, similar to the EMD B-units.

When full production was ordered, it was Brush that got the business - but with the BRCW design.

Seemingly BRCW made a management decision to get out of the rolling stock business while Brush needed propped up for political reasons of one kind or another.

 

[Taunton]

I'm almost surprised they didn't try a cabless version of one of the Type 1s purely to work in multiple, similar to the EMD B-units.

B units were found to be an inflexible nuisance. They originated because the earlier EMD and other multi-unit locos had manual controls of certain features, particularly the radiator shutters, and the fireman needed to go back, via the gangways (like corridor coaches) between the units (hence no nose ends could be there), to open and close them, deal with the steam heat generators, and such like. Thereafter, once those were automated, it still seemed like an efficiency, as the cab and its controls is a significant part of the loco cost. However, it is also the source of many unreliabilities, and if the lead cab develops a defect you cannot just detach it out on the line and drive from the second unit if it is a B unit - the whole formation becomes a failure. Hence the US (particularly Amtrak) practice of running triple/quad formations with the second unit facing forwards as well, in case of need.

 

[RLBH]

B units were found to be an inflexible nuisance.

And would therefore fit in with all the other bad ideas that were given a chance to demonstrate their uselessness by the Pilot Scheme?

 

[etr221]

B units were found to be an inflexible nuisance. They originated because the earlier EMD and other multi-unit locos had manual controls of certain features, particularly the radiator shutters, and the fireman needed to go back, via the gangways (like corridor coaches) between the units (hence no nose ends could be there), to open and close them, deal with the steam heat generators, and such like. Thereafter, once those were automated, it still seemed like an efficiency, as the cab and its controls is a significant part of the loco cost. However, it is also the source of many unreliabilities, and if the lead cab develops a defect you cannot just detach it out on the line and drive from the second unit if it is a B unit - the whole formation becomes a failure. Hence the US (particularly Amtrak) practice of running triple/quad formations with the second unit facing forwards as well, in case of need.

The other point in regard to the original 'streamliner' diesels is that to a significant extent the various A-B, A-B-A, etc. combinations were initially at least regarded as single locomotives, with a single number (and suffix letter for each unit), primarily for manning/union agreement purposes (only the earliest had fixed couplings); and that - to an extent - aesthetics mattered (or were felt to).
The various Soviet/Russian multi unit diesels and electrics were also, I understand, regarded, and numbered a single locomotives

 

[Bevan Price]

The Type 1s and many Type 2s were mostly built to replace the large numbers of steam (especially 0-6-0) freight locos on trip workings and the lighter freight services -- both of which started to disappear whilst the new diesels were still being built. In consequence, other uses were found, including using them in pairs on heavy coal / stone trains, especially at locations where Classes 40 / 45 /46 were too heavy, or were otherwise unsuitable (e.g. due to long wheelbases)

 

[Spartacus]

I wonder what the aversion was to having a Type 1 with the normal arrangement of a cab at each end. There was every alternative conbination, none well received

I guess as most type 1s were expected to do a lot of shunting or trip work having one can would save a fair bit of time compared to changing ends, and offer a better view than driving from the wrong end. They typically were compared to steam locos more than ‘main line’ diesels, and I doubt any offered a worse view out, although I bet the 16s were just as bad.