Why was the Class 45 kept in service over the Class 40?

[BeijingDave]

A straightforward question:

As a very junior spotter (accompanied by a very knowledgeable uncle, now unfortunately deceased) in the early 80s, a frequent trip was from Warrington BQ up to York to the National Rail Museum (and the Jorvik Viking Centre).

As I recall, 45s and occasionally 40s headed this service, which may have been ex-Llandudno to the North East. If there was no loco-hauled traction, we would hop on a DMU to Newton-le-Willows to catch one ex-Liverpool.

Having been built around the same time, why was the 45 preferred over the 40? What little I know of the 40s is that they had less tractive power but better acceleration which may have suited a stop-start service such as Llandudno-the North East (with its various North Wales stops and Newton-le-Willows, Stalybridge, Huddersfield, Dewsbury etc).

== Doublepost prevention - post automatically merged: 5 Jan 2025 ==

I do vaguely recall having a pinched window display sticker Llandudno-Newcastle (or maybe Scarborough) which ran to at least three lines of stops.

 

[Wilts Wanderer]

Class 40s were essentially underpowered and overweight; at 2000hp they were at the bottom of the Type 4 classification. The Peaks were better, with an additional 500hp which made them almost equal to a Class 47, so the performance was much better than a 40. My Dad remembers trips over the Leeds-Huddersfield-Manchester route and if a 40 turned up vice Pram it was going to be a real grind up the hills with consequent delays.

I assume 40s were preferred over Peaks for freight work though, presumably they were better sloggers although plagued with inadequate cooling particularly in hot weather?

There may also have been an Electric Train Heat consideration - presumably both types had fairly primitive systems but was the Peak perhaps better in this regard?

 

[12LDA28C]

A straightforward question:

As a very junior spotter (accompanied by a very knowledgeable uncle, now unfortunately deceased) in the early 80s, a frequent trip was from Warrington BQ up to York to the National Rail Museum (and the Jorvik Viking Centre).

As I recall, 45s and occasionally 40s headed this service, which may have been ex-Llandudno to the North East. If there was no loco-hauled traction, we would hop on a DMU to Newton-le-Willows to catch one ex-Liverpool.

Having been built around the same time, why was the 45 preferred over the 40? What little I know of the 40s is that they had less tractive power but better acceleration which may have suited a stop-start service such as Llandudno-the North East (with its various North Wales stops and Newton-le-Willows, Stalybridge, Huddersfield, Dewsbury etc).

A major consideration would have been train heating capability (or lack of). 40s were built with boilers to provide steam heat whereas the 45/1s had ETH which was rather more suitable for air-conditioned stock which was why 45s lasted until 1988/89. The additional 500hp power rating over a Class 40 would also have been useful over the gradients on the TransPennine route.

 

[Magdalia]

Class 45 had significantly more power than class 40, 2500hp v 2000hp.

By the 1980s, when steam heat was being phased out, class 45/1 also had the significant advantage of being equipped with electric train heating.

 

[BeijingDave]

Class 40s were essentially underpowered and overweight; at 2000hp they were at the bottom of the Type 4 classification. The Peaks were better, with an additional 500hp which made them almost equal to a Class 47, so the performance was much better than a 40. My Dad remembers trips over the Leeds-Huddersfield-Manchester route and if a 40 turned up vice Pram it was going to be a real grind up the hills with consequent delays.

I assume 40s were preferred over Peaks for freight work though, presumably they were better sloggers although plagued with inadequate cooling particularly in hot weather?

There may also have been an Electric Train Heat consideration - presumably both types had fairly primitive systems but was the Peak perhaps better in this regard?

Thanks for the enlightening reply. What does the bolded term mean, please?

== Doublepost prevention - post automatically merged: 5 Jan 2025 ==

This service may have also been interesting for the number of remodeled stations and now out-of-use/renumbered platforms it served. I distinctly remember leaving Platform 5 at WBQ (now Platform 4), passing through one of the higher numbered platforms at Manchester Victoria (presumably 11 or 12) and also stopping at a probably now renumbered platform at Stalybridge and Leeds.

 

[LNW-GW Joint]

I think braking came into the equation too, as many of the class 40 fleet were still equipped for vacuum braking only, while the class 45/46 fleets were converted to dual braking.

 

[Gloster]

I would think that the decline of vacuum-braked wagonload traffic was a factor. The 40s had been reasonably effective on this, but they were not really suitable the air-braked network.

 

[Harpo]

Freight type 5s emerged from the late 70s onwards and younger 37s proved capable of being re-engineered to match or exceed class 47 freight haulage capabilities, while the passenger side was working on eliminating steam heat and many smaller locos were able to assist with that on small loads, especially as DMUs were dieing on their feet. Something was always going to fall out of the bottom.

Class 40s were underpowered, not all dual braked, had no ETH capability and were plain life expired. (And I was a big fan!) Class 45 had a Darwinian reprieve.

 

[eastwestdivide]

What does the bolded term mean, please?

Vice = railway jargon for "instead of"; pram I can only guess (despite being a spotter back then) = basher jargon for the booked class 45 or 47

 

[12LDA28C]

I think braking came into the equation too, as many of the class 40 fleet were still equipped for vacuum braking only, while the class 45/46 fleets were converted to dual braking.

By 1981 the majority of 40s had been dual braked and by 1983 very few VO 40s remained in traffic.

 

[Wilts Wanderer]

Thanks for the enlightening reply. What does the bolded term mean, please?

Autocorrect fail, was definitely typed as ‘peak’!

I hadn’t twigged (being born in the 80s) that 40s never had any form of ETH so that will have been a major factor. Steam heat was largely confined to the dustbin by the late 70s / early 80s IIRC.

 

[Sun Chariot]

By 1981 the majority of 40s had been dual braked and by 1983 very few VO 40s remained in traffic.

I think 40009 was the last surviving vac only Whistler.

I all but missed the 40s in service - I saw two sat just outside Carlisle in early 1984; I saw Auerol in its departmental life.
Other 40s I saw, were on death row at Swindon Works (1985) and Crewe Works (1986).

 

[norbitonflyer]

The Peaks had a lot in common with the 47s - indeed the engines, generators and other electrical equipment for the first twenty D1500s had originally been intended for further class 46s (one can only speculate what numbers the last sixteen would have been given.)
This commonality may have been a further reason for the longevity of the Peaks.

 

[Sir Felix Pole]

The Peaks had a lot in common with the 47s - indeed the engines, generators and other electrical equipment for the first twenty D1500s had originally been intended for further class 46s (one can only speculate what numbers the last sixteen would have been given.)
This commonality may have been a further reason for the longevity of the Peaks.

Although the Cl 45s had Crompton Parkinson rather than Brush generators and traction motors, and ironically lasted longer than the newer Cl 46s which proved less reliable.

 

[Gloster]

The Peaks had a lot in common with the 47s - indeed the engines, generators and other electrical equipment for the first twenty D1500s had originally been intended for further class 46s (one can only speculate what numbers the last sixteen would have been given.)
This commonality may have been a further reason for the longevity of the Peaks.

Indeed, one can but speculate, but a reasonable assumption is that they would probably have been numbered from D400 up. This would, in turn, probably have meant that the Class 50 would have been D500-549.

(I make it fourteen, not sixteen.)

 

[Magdalia]

The Peaks had a lot in common with the 47s - indeed the engines, generators and other electrical equipment for the first twenty D1500s had originally been intended for further class 46s (one can only speculate what numbers the last sixteen would have been given.)

Indeed, one can but speculate, but a reasonable assumption is that they would probably have been numbered from D400 up. This would, in turn, probably have meant that the Class 50 would have been D500-549.

(I make it fourteen, not sixteen.)

There is no need for speculation, after D199 the numbers were going to continue D1500-13. See Brian Webb's Sulzer Diesel Locomotives of British Rail page 34.

I hadn’t twigged (being born in the 80s) that 40s never had any form of ETH so that will have been a major factor.

99.5% correct. D255 was briefly fitted with experimental ETH.

 

[norbitonflyer]

(I make it fourteen, not sixteen.)

Quite so. 194 to 199 is six numbers.

 

[Harpo]

Although the Cl 45s had Crompton Parkinson rather than Brush generators and traction motors, and ironically lasted longer than the newer Cl 46s which proved less reliable.

Class 46’was a Brush product. They supplied 500+ locos needing derating to survive and 300+ locos needing replacement EE power units to survive. NBL ought to glow by comparison.

 

[billh]

I think 40009 was the last surviving vac only Whistler.

I all but missed the 40s in service - I saw two sat just outside Carlisle in early 1984; I saw Auerol in its departmental life.
Other 40s I saw, were on death row at Swindon Works (1985) and Crewe Works (1986).

Yes, I remember 40009 underway at Guide Bridge, VOLO (Vacuum Only,LOngsight) written on the front . A bit of a celebrity loco at the time. I'm old enough to have seen EE type4s on Manchester -London trains when they were new- we called them MLDs (Main Line Diesels).

 

[gg1]

I hadn’t twigged (being born in the 80s) that 40s never had any form of ETH so that will have been a major factor. Steam heat was largely confined to the dustbin by the late 70s / early 80s IIRC.

More the latter. ETH gradually replaced steam heating over the course of the 70s but steam heat was still relatively common by the end of the decade. By around 1985 however, it had been eliminated from most of the network the last hold outs being in Northern Scotland.

 

[Merle Haggard]

There's been reference to the greater installed horsepower of 47s over 40s and the advantage of the former in also having ETH; but didn't ETH reduce the drawbar horsepower available? Any ideas of a likely value - you just need to know the kw of an electric heated train and convert to power in terms of hp.

I never understood the enthusiasm for EE4s; when they replaced steam on the West Coast their shortcomings were immediately apparent. I spotted at Roade where there was I think a 1 in 300 climb from the South. Watching, first, a Pacific romp effortlessly (ok, the fireman was puttiing in some effort!) past on 16 by followed by an EE4 on 11, full power thrashing away and grinding past at half the speed. Initially, the EE4s only took over 6P and 7P steam diagrams, the 8P ones were beyond them. The 8P trains loaded to 16; the solution - cram everyone into 11 cars so the EE4s could take over and scrap the Pacifics at a stroke.
I also had an excruciating run behind an EE4 on the down Royal Scot in January 1963; boiler out of action, so as well as the coaches the EE4 had to lug a Black 5 for steam heat. Max speed about 50 mph on the downhill sections.
The loco handbrakes on EE4s also seemed a bit sketchy; when stabled they had to be scotched presumably as a result of experience.

 

[D6130]

The loco handbrakes on EE4s also seemed a bit sketchy; when stabled they had to be scotched presumably as a result of experience.

Yes, I can recall several occasions when they went walkabout unaccompanied....often ending-up being derailed at the end of a sand drag. (or - to use the technical term - suffering an earth fault!)

 

[Harpo]

I never understood the enthusiasm for EE4s;

For me, same as 20s 37s & 50s, those wonderful EE sounds. Lower power was never a problem for me as a basher, you got full thrash for longer.

The EE4’s low power was probably why drivers in some places called 47s a ‘4 and a half’, although many drivers much preferred a ‘Crompton’ (45) over a 47 not least because of draughts.

 

[hexagon789]

For me, same as 20s 37s & 50s, those wonderful EE sounds. Lower power was never a problem for me as a basher, you got full thrash for longer.

The EE4’s low power was probably why drivers in some places called 47s a ‘4 and a half’, although many drivers much preferred a ‘Crompton’ (45) over a 47 not least because of draughts.

45s also tend to accelerate slightly quicker in the mid-speed range, due to having more and better spread field diverts. (5 vs 3 on a 47)

 

[Merle Haggard]

45s also tend to accelerate slightly quicker in the mid-speed range, due to having more and better spread field diverts. (5 vs 3 on a 47)

In my RfD days colleagues at Tinsley had a much higher opinion of 47s than 37s from an engineering perspective because of, amongst others, the field divert arrangement. I'm not sure whether the EE4s had the same arrangement, though. The criticism was that, on the Brush system, when the field divert (going up in speed) happened the pump setting on the engine was simultaneously adjusted. On the 37's the field divert happened in isolation - it increased the load on the generator which then loaded up the engine, almost stalling it. It was the drop in revs that then triggered an increase in the fuel, so there was a delay before this happened as events worked through the system . This was the reason on a 37 that they took off well but then revs dropped so dramatically at divert speed - a bit like someone racing off in first then changing up 2-3 gears at once in a car. Hope this is an accurate representation.

 

[hexagon789]

In my RfD days colleagues at Tinsley had a much higher opinion of 47s than 37s from an engineering perspective because of, amongst others, the field divert arrangement. I'm not sure whether the EE4s had the same arrangement, though. The criticism was that, on the Brush system, when the field divert (going up in speed) happened the pump setting on the engine was simultaneously adjusted. On the 37's the field divert happened in isolation - it increased the load on the generator which then loaded up the engine, almost stalling it. It was the drop in revs that then triggered an increase in the fuel, so there was a delay before this happened as events worked through the system . This was the reason on a 37 that they took off well but then revs dropped so dramatically at divert speed - a bit like someone racing off in first then changing up 2-3 gears at once in a car. Hope this is an accurate representation.

The re-geared 37s with CP7 bogies (80mph) have their two diverts come in at fairly low speeds - 20 and 35mph.

Original 90mph (106mph gearing) 37s have their divert speeds set at 26 and 49mph, and upper speed performance seems much better by comparison looking at performance logs.

Though, as I understand it while the refurbished 37s with an alternator can be immediately opened to full power, unrefurbished ones could be easily overloaded at low speeds, so initial acceleration is probably better on refurbished examples?

47s can be opened to full power straightaway with the only potential issue being rail conditions, the locos themselves can take it.

 

[norbitonflyer]

Yes, I can recall several occasions when they went walkabout unaccompanied....often ending-up being derailed at the end of a sand drag. (or - to use the technical term - suffering an earth fault!)

One - albeit not a handbrake fault but faulty brake blocks - ran away down Cowlairs Bank and collided heavily with the coaches of the Fort William sleeper sitting in Queen Street - a rude awakening for those still in bed.

 

[Cowley]

Just to say that the interesting side discussion about the class 37 trials is now here:

Double class 37 trials on the Paddington to Cardiff route 1960s.

The re-geared 37s with CP7 bogies (80mph) have their two diverts come in at fairly low speeds - 20 and 35mph. Original 90mph (106mph gearing) 37s have their divert speeds set at 26 and 49mph, and upper speed performance seems much better by comparison looking at performance logs. Though, as I...

www.railforums.co.uk

 

[hexagon789]

Just to say that the interesting side discussion about the class 37 trials is now here:

Double class 37 trials on the Paddington to Cardiff route 1960s.

The re-geared 37s with CP7 bogies (80mph) have their two diverts come in at fairly low speeds - 20 and 35mph. Original 90mph (106mph gearing) 37s have their divert speeds set at 26 and 49mph, and upper speed performance seems much better by comparison looking at performance logs. Though, as I...

www.railforums.co.uk

Thanks @Cowley . You were too quick for me, with my last post!

 

[Cowley]

Thanks @Cowley . You were too quick for me, with my last post!

No worries.

I’ve always found this quite an interesting subject I must say.