Class 50 why fifty.

[John Tomlinson]

Going back to the original question, why 50 and not more or less, the answer may rest in that there were a great many more loco classes and locos in total working at that time, so perhaps the order volume wasn't so precisely determined as it would be today. One could equally ask, for example, why 512 class 47's, or 308 class 37's. 50 locos was quite a small order for a mainline loco at the time, and maybe the idea was that if need arose they'd have another 50. Pure surmise on my part I know.

 

The other factor is that BR was in a state of serious flux at the time, there would have been questions already stirring about the diesel hydraulic program, and in addition freight was falling through the floor as the country acquired an improved road system, so traffic needs must have been uncertain to put it mildly.

 

As a teenage spotter I can verify that standing on Preston station circa 1970, you could almost guarantee to see around half the class between 09.00 and 17.00 on a single day, so their utilisation can't have been that low.

 

John.

Edited June 20, 2018 by John Tomlinson

[Titan]

  Never anywhere in my entire railway experience did I come across so many loco failures in traffic, let alone of a single Class, on one day and it was well atypical of a Summer Saturday where there were often a few failed locos to replace. 

 

Oh that's nothing.  on one particular day when the Networkers were not long introduced, they managed a fleet average of 46 miles between failures. To this day I am not entirely sure how this was possible - each train must have broken down at least twice during the day. That surely has to be the worst reliability since before 1800, and I don't mean six o'clock!

[kevinlms]

To answer the question, they multiplied the square root of reliability by the total mileage the type was meant to cover minus cost of spare parts to the power of the chairman of EE’s annual salary and arrived at 50.

Possibly, but if 49 had been built or 51, then the question would be why 49/51 and not 50?

 

BTW, wasn't there a 101 Hymek's built?

[Holmesfeldian]

Possibly, but if 49 had been built or 51, then the question would be why 49/51 and not 50?

 

BTW, wasn't there a 101 Hymek's built?

 

 

There were but the original requirement was 45 locos (D7000-D7044). Subsequent additional orders made it up to 101 in total (conveniently stopping at D7100!).

 

Just to fan the flames further, wasn't there 999 BR Standard steam locos built? 

 

Why not 1,000? :-)

Edited June 20, 2018 by Holmesfeldian

[keefer]

why fifty? it was possibly as many as BR could justify, that the Govt. was willing to pay for. The late '60s heralded a new area of BR having to justify what they wanted - it was no longer possible to have large orders for locos/stock just because that what was wanted.

When the mk2 coaches came in, BR originally wanted equivalent types to the existing mk1s and were told 'no chance'. Hence 14 different types became 5 - brake first & second, open second (some SO, mainly TSO) and first corridor. No new sleepers/catering/full brake vehicles (mk1s retained) and the amounts of vehicles built (esp. in the mk2d-f range) were under constant scrutiny. Basically less coaches were approved and those built had to earn their keep (more use due to the introduction of semi-fixed sets and tighter coach diagramming).

 

In the late '60s there wasn't enough work for all the electric locos, so the troublesome 83s & 84s were stored as surplus to requirements. But when full WCML electrification was underway, more locos were needed again. However only 35 new locos (class 87) were authorised, so the shortfall had to be made up by repairing/refurbishing the stored locos back into traffic.

 

As an aside, had more 50s been built we might have seen them on the Edinburgh-Glasgow push-pulls. I believe they undertook timing runs but the plan never went any further - the 50s were all needed for the accelerated WCML services north of Preston (the longest trains needed at least 4000hp)

 

EDIT: apologies for repeating a lot of info from my post on p.1 of this thread!

Edited June 20, 2018 by keefer

[slilley]

why fifty? it was possibly as many as BR could justify, that the Govt. was willing to pay for. The late '60s heralded a new area of BR having to justify what they wanted - it was no longer possible to have large orders for locos/stock just because that what was wanted.

When the mk2 coaches came in, BR originally wanted equivalent types to the existing mk1s and were told 'no chance'. Hence 14 different types became 5 - brake first & second, open second (some SO, mainly TSO) and first corridor. No new sleepers/catering/full brake vehicles (mk1s retained) and the amounts of vehicles built (esp. in the mk2d-f range) were under constant scrutiny. Basically less coaches were approved and those built had to earn their keep (more use due to the introduction of semi-fixed sets and tighter coach diagramming).

 

In the late '60s there wasn't enough work for all the electric locos, so the troublesome 83s & 84s were stored as surplus to requirements. But when full WCML electrification was underway, more locos were needed again. However only 35 new locos (class 87) were authorised, so the shortfall had to be made up by repairing/refurbishing the stored locos back into traffic.

 

As an aside, had more 50s been built we might have seen them on the Edinburgh-Glasgow push-pulls. I believe they undertook timing runs but the plan never went any further - the 50s were all needed for the accelerated WCML services north of Preston (the longest trains needed at least 4000hp)

 

EDIT: apologies for repeating a lot of info from my post on p.1 of this thread!

To answer the question again, the reason why 50 were built was because BR had identified that is what they had identified they needed.

 

This which is from Class 47 50 Years of Locomotive History explains what was going on at the time. Certainly there was an element of what BR thought they could get Government approval for.

 

Although orders had been placed for a total of 512 Brush Type 4 locomotives, the BR Board/Industry Policy Committee, a body comprising representatives from BR and manufacturers such as Brush, were advised by BR of a possible requirement for a further 150 Type 4 locomotives at their March 1964 meeting. This number was later reduced by the BR Board to 100. Both Brush and English Electric provided the Board with prices for 110 locomotives, which were summarised in a memo to the Supply Committee in July 1965. The prices quoted did not include the provision of a train heating boiler, although they allowed for the appropriate fittings should one be required.  Of the options proposed, the CE (T&RS) considered that the provision of an English Electric engine in a Brush Type 4 locomotive was technically unacceptable for several reasons. It would produce a locomotive with an untried combination of engine and electrical components, some of the equipment and mechanical parts would need redesigning, and development work was likely to be required before production could begin. In their offer English Electric said they were prepared to enter into a hire arrangement, while Brush said they were considering the terms on which they would be prepared to hire locomotives to BR. Brush’s schedule would see locomotives delivered between September 1966 and February 1967 if a Sulzer engine was required, and between October 1966 to November 1967 if the English Electric engine was chosen. English Electric’s schedule was to deliver fifty locomotives to their design between January 1967 and January 1968.

Table 4: Results of 1965 tender for Type 4 locomotives

a) Brush Design

No of Locomotives Estimated Prices per Locomotive

  Sulzer engine                 English Electric engine

Brush

25 £122,200 £111,200

50/55 £121,200 £109,800

110 £120,000 £108,300

BR Workshops 25 £121,700 £109,600

55 £121,200 £108,800

b) English Electric Design

No of Locomotives Estimated Prices per Locomotive

Type 4 DP2

50 £105,400 £106,100

110 £102,400 £103,300

John Ratter, the BR Board Member for Engineering, presented a paper on the availability of Sulzer-powered Type 4s, and the options for future Type 4 locomotive purchases, for the Board to consider in October 1965. He set out details of availability plus a summary of the main technical issues associated with not only the Brush Type 4s but also with the three variants of BR/Sulzer Type 4.  At the time, 402 Brush Type 4s had been delivered, returning an average availability of 75%. The main concern with them was the cracking of the Sulzer engines, the full extent of which was only just becoming known. Ratter’s view was that the Board had two options, the first of which was to purchase a further quantity of Brush Type 4s. These would incorporate all the modifications found necessary during the three years’ experience of operating the fleet. The second option was to purchase a quantity of what he described as ‘DP2 locomotives’ from English Electric. While both options had their advantages, his preference would be for the English Electric design. The BR Board accepted his recommendation, although they were only able to gain permission from the Ministry of Transport to hire 50 new locomotives. With this acquisition, BR’s Type 4 locomotive fleet was completed. In October 1965, BR entered into an agreement with English Electric for the construction and hire of 50 locomotives based upon DP2. The first of these entered service in September 1967, and were later designated Class 50.

[The Johnster]

Don't forget that the WCML's immediate requirement was for a loco that substituted for a 4.000hp electric loco for the promised acceleration of the Glasgow trains when the electrification was deferred north of Weaver (1966?).  The obvious solution appears at first sight to be double headed 47s, and ordering a further 50 of these, but eth was required and the power meant double heading with multiple unit control; this cannot be done with 47s!  

 

Neither can 110mph running, which was another requirement.  The only locos that could do this in the mid 60s were the Deltics, which the WCML had had experience of a decade earlier and were impressed with but didn't want to be involved with on maintenance grounds, and DP2; problem solved, 50x DP2 with control cables and eth in redesigned bodyshells.  But troublesome electronics had to be included in order to satisfy the multiple unit requirement.  The only other locos the WCML had available were the 40s, already obsolete and also not capable of multiple working; there was probably room on board these behemoths to include eth and multiple control circuitry, but, even in the mid 60s when all this was being planned, nobody wanted the better part of 300 tons of loco lumbering around the place and delivering only 4,000hp on a good day, the bare minimum for the job.  40s couldn't run at 110mph either.

[keefer]

Class 40s already had Blue Star MU eqpt but as you say, weren't suited to high-speed running anyway.

I think the WCML was only 100mph then as this was the max speed of the locos and Mk1 & 2 coaches. HST and APT aside, 110mph only came in the mid-80s with the Mk3 coaches (and special conditions for the Mk1 NHA BG)

[newbryford]

There were but the original requirement was 45 locos (D7000-D7044). Subsequent additional orders made it up to 101 in total (conveniently stopping at D7100!).

 

Just to fan the flames further, wasn't there 999 BR Standard steam locos built? 

 

Why not 1,000? :-)

 

It really should have been more but some prospective orders were never followed up. 72010-72024, 75080-75089, 82045-82062

(And then some would argue that it would have been 998 if 46202 hadn't been written off at Harrow & Wealdstone and a replacement in the form of 71000 was built)

 

Cheers,

Mick

[dvdlcs]

There were but the original requirement was 45 locos (D7000-D7044). Subsequent additional orders made it up to 101 in total (conveniently stopping at D7100!).

 

Veering way off-topic, but I seem to remember reading that the 101st Hymek was a mistake, and only 100 were intended? Someone forgetting that the first was 7000 and not 7001.

 

Any truth, or an urban myth?

[The Johnster]

Veering way off-topic, but I seem to remember reading that the 101st Hymek was a mistake, and only 100 were intended? Someone forgetting that the first was 7000 and not 7001.

 

Any truth, or an urban myth?

 

No idea, but 101 is an odd number (literally) to order.  D7101-99, or perhaps D7200, were to be lower geared versions to replace the 56xx for South Wales workings, with a top speed of 70mph; in the event Beyer Peaccock's cashflow problems sank the company after they had paid for the materials for these locos and 37s, which EE could supply quickly and were already tried and tested on the ER and NER, stepped in to the breach.

 

Or is this an urban myth as well?

[The Stationmaster]

Veering way off-topic, but I seem to remember reading that the 101st Hymek was a mistake, and only 100 were intended? Someone forgetting that the first was 7000 and not 7001.

 

Any truth, or an urban myth?

 

The Hymeks were ordered in three batches - the original 45, then a batch of 50, and finally a batch of 6.  The original intention to order a further 200 was dropped at fairly short notice when a policy decision was made to standardise on diesel electric designs for future orders so it is possible  (but I have never seen written evidence) that the final six might have been part of a cancelled order left in place to keep Beyer Peacock in work until new orders could be placed on them.  Hymek production ran from 1961 to 1964 with thh final six being ordered in 1961.  The Beyer Peacock factory then moved on to building the Clayton Type 1 centre cab design in 1964/65 and finally some of the BR standard Type 2 diesel in 1965/66 until the closure of the works but in both cases the rate of construction was relatively slow suggesting that the workforce was probably already being rundown  

 

The availability of only 101 Hymeks definitely curtailed the planned pace of elimination of the 'Hall' and 'Grange' classes and the diesel electric order was split between the EE Type 3 (later Class 37) basically intended to dieselise South Wales secondary routes mainly on freight work and the Brush Type 4.

 

The EE Type 3 had been tested against a Hymek on the South Wales Valleys and while the Hymek showed some superiority in load shifting, with less inclination to slip due to having what almost amounted to 4 coupled axles instead of six independently powered axles, the EE loco had the critical advantage of being much heavier which was far better at braking trains of unfitted wagons on the step gradients in the area plus because of its two extra axles it had lower axle loadings than the Hymek.  So the decision was made to order the EE design for dieselisation of most South Wales freight work and that of course also dovetailed nicely with BR's pro-diesel electric policy.  The other advantage of the EE design was that it was being built concurrently in two factories and thus offered a faster rate of delivery than would have been possible with the Hymeks coming out of a single factory although the output per factory wasn't spectacularly different when BP were going at full pace. 

 

Quite how many Hymeks would have arrived on the WR if they had been chosen for both replacement of mixed traffic 4-6-0s/smaller engines and the South Wales Valleys freight work is perhaps open to conjecture.  There definitely seem never to have been any plans to have any sort of modification of them for freight work and of course they were effectively in two distinct groups by 1965 following various problems which led to half of the class having their engines derated while the other half had one gear locked out (which might have been useful on heavy freight work with slow trains - assuming they could actually stop the trains once they had started them!).  Basically as freight locos they were far too light light, and therefore under-braked for loose coupled freight train working and this was no doubt fully appreciated on the WR when it was decided to try an EE Type as the potential candidate for the South Wales Valleys.

[The Johnster]

The origin of the lower geared 70mph Hymek for South Wales freight work came from Canton drivers I worked with in the 70s; this myth was widely believed amongst them and B-P's demise on having ordered and paid for materials and not being able to deliver the locos in time for BR to pay for them and bail them out.  

 

You seem to have the full story chapter and verse, as I'd expect, Mike, and I am grateful for your putting us straight on this.  I don't personally reckon the Hymeks would have been up to the rigours of Valleys work; not enough brake force as you say and not enough T.E. either.  My personal view is that the Westerns were far and away the best of the hydraulics when it came to heavy freight; massive T.E. and a fair bit of braking power.  Sadly, they ran very roughly, with a violent vertical oscillation, at precisely the 55-65mph speed range that was required for the air braked block trains that might have kept them in employment in the mid 70s; on a 45mph maximum South Wales-Acton coal train they were peerless!