Difference in performance of class 31 & 37

[russ p]

3 minutes ago, rogerzilla said:

Pig ugly though (most things designed around gangway connections weren't lookers; EE locos with a "nose" got away with it). The Class 33s are quite pretty by comparison with the 31s.

 

The design was certainly improved upon by the design panel the original brush drawings make the NBL type twos look ecstatic with happiness! 

[adb968008]

5 hours ago, Steven B said:

Class 31s lingered on long after the other Type 2s so they couldn't have been all bad. 

 

Steven B

they were pretty diabolical in the late 1980’s early 1990’s.

I think they only survived due to strength in numbers..

24/25’s/27’swere equally knackered but Sulzer power was on its way out with 45/46’s... remember 47’s were called duffs too for a reason.

 

i’m surprised class 26’s didnt replace 31’s, but there werent enough of them about, which meant later scenes of class 33’s in Scotland.

 

fwiw... 33’s have fared better in privatisation and preservation, even today theres more overall 33’s both mainline registered and actually in working order than class 31’s... A poor 33 was always better than a good 31 whenever Ive seen them.

Edited December 1, 2019 by adb968008

[russ p]

But a 33 is a type 3 if being pedantic 

 

[Mike Storey]

46 minutes ago, rogerzilla said:

Pig ugly though (most things designed around gangway connections weren't lookers; EE locos with a "nose" got away with it). The Class 33s are quite pretty by comparison with the 31s.

 

Eye of the Beholder - I think they are one of the best looking BR locos on offer, but then, I grew up with them.

[adb968008]

1 hour ago, russ p said:

But a 33 is a type 3 if being pedantic 

 

So is a 31...

hence a better comparison.

 

with an EE engine thats 1470hp

against a 33’s 1550hp

vs a 26’s 1160hp

or a 37’s 1750hp

 

obviously weight and axles plays a part, in both cases against the 31.

 

 

Edited December 1, 2019 by adb968008

[stovepipe]

Another factor in their longevity was that the EE engine was down-rated to match the original electrical equipment output, and together with the generally better EE reliability, meant ownership was a less costly proposition. The better RA mentioned earlier can't gave harmed their case either.

[russ p]

I cant remember what job I did at thornaby on night but there was no pairs of 37s available for a steel job out of lackenby,  was either corby or etruria but I took 3 31s instead and they performed fantastically 

[Foden]

Really appreciate all the replies, it makes fascinating reading!

[Bert Cheese]

I'm not familiar with 31's, but have read that the engine room door could easily be removed and slung between the seats as an impromptu bed when on ballast jobs...anyone care to confirm?

[russ p]

2 minutes ago, Bert Cheese said:

I'm not familiar with 31's, but have read that the engine room door could easily be removed and slung between the seats as an impromptu bed when on ballast jobs...anyone care to confirm?

 

Not true I'm afraid,  if you did take the door off noise would be horrendous so no sleep. And where would your mate go

[Bert Cheese]

3 minutes ago, russ p said:

 

Not true I'm afraid,  if you did take the door off noise would be horrendous so no sleep. And where would your mate go

 

Fair comment, though I was thinking of the pure physicality of it regardless of noise...shutting the engine down would probably be impractical in most cases anyway...

 

[pete_mcfarlane]

On 30/11/2019 at 18:26, Robert Shrives said:

it is just a statement of the times in which it was planned where steam engine designers were getting to hand with diesels. compare the D600 to D800 for how stressed light weight bodies came to the fore. 

Robert      

 

The irony there is that the D800 is actually the older design of the two, being essentially a DB V200 shrunk to fit the UK loading gauge. The archaic design of the D600 being down to internal BR politics. 

[Titan]

Why do people keep saying class 31's are type 3? Is it because the class number starts with a 3 and people are easily confused by it?

[MidlandRed]

Also remembering the transfer of class 31s and 25s to the WR was intended to replace class 22s - the first transfers being to OOC for Paddington empty stock trains. Given their reputation on the ER they should have been very competent performers on type  2 duties, especially given their horsepower advantage over other type 2 classes. 

 

How class 37 compared with class 35 would be interesting! 

[The Stationmaster]

1 hour ago, MidlandRed said:

Also remembering the transfer of class 31s and 25s to the WR was intended to replace class 22s - the first transfers being to OOC for Paddington empty stock trains. Given their reputation on the ER they should have been very competent performers on type  2 duties, especially given their horsepower advantage over other type 2 classes. 

 

How class 37 compared with class 35 would be interesting! 

They were perfectly ok on Paddington ECS workings plus various lighter trains they took over from the D63XX or,  in one case, the D95XX 0-6-0.

 

Comparisons between the EE Type 3 and the Hymek is an interesting one.  The EE Type 3s won out or South Wales Valleys etc dieselisation because of their greater weight and extra axles which made a big difference with braking unfitted trains although the Hymeks had the advantage of, in effect, having coupled axles on each bogie plus the bogies being coupled to each other which reportedly made them more sure footed.  But the Hymeks had encountered some problems which led to half the class being temporarily derated by about 100hp and the half having first gear locked out.  I only ever rode on de-rated examples and they didn't seem to perform any worse than the originals in terms of acceleration and maximum speed on passenger workings.  And the Hymeks were without a doubt one of the best riding diesel locos BR ever had - 'as smooth as a coach' was how many footplatemen described them and I certainly found their riding impressive at speed on London commuter trains, definitely smoother than a loco sitting on the standard 3 axle English Electric bogie although it was a good riding bogie.

 

The Hymeks clearly could never have undergone the various changes leading to the various  Class 37 sub-classes but the engine was capable of uprating although whether it was the right engine/transmission combination will always be open to question.  But they went because they were disel hydraulics - simple as that.

[The Johnster]

Hymeks were lovely to work on.  Lovely ride on long wheelbase bogies, quiet, draughtproof, and comfortable cab, door windows that opened (very useful when you were shunting and passing handsignals to the driver from the other side of the cab), easy access compared to the overhang and narrow passageways of the Westerns, and very lively performance, pocket rockets.  Seeing a 75 ton loco with 4 driven axles lift a 700 ton cement train out of the very steep siding at Aberthaw Cement Works was a visual vindication of the efficacy of the WR's hydraulic principle; 37s, good as they were, would have been constantly tripping out.  We were told at the time that they were withdrawn because of the requirement for air brakes, which could not be fitted as there was nowhere to put the equipment, but policy was to dispense with hydraulic transmission by that time.

[Foden]

Interesting, you hear largely favourable stories of how diesel hydraulics performed on the Western region. It would appear from the outside looking in that the classes were (for the most part) well designed, good performers, stood up rather well to the rigours of the work they were asked to do (certainly no worse than many other early pilot DE locos), and generally looked upon favourably by the crews that worked and maintained them.

 

So unless, with respect, many of these recollections are nostalgic memories through maybe slightly rose tinted glasses, one wonders why BR were so adamant not to take the diesel hydraulic principle any further?

 

Politics? Expense? Personal favouritism at board level?

[pheaton]

17 hours ago, adb968008 said:

they were pretty diabolical in the late 1980’s early 1990’s.

I think they only survived due to strength in numbers..

24/25’s/27’swere equally knackered but Sulzer power was on its way out with 45/46’s... remember 47’s were called duffs too for a reason.

 

i’m surprised class 26’s didnt replace 31’s, but there werent enough of them about, which meant later scenes of class 33’s in Scotland.

 

fwiw... 33’s have fared better in privatisation and preservation, even today theres more overall 33’s both mainline registered and actually in working order than class 31’s... A poor 33 was always better than a good 31 whenever Ive seen them.

the issue with 31s is the unique centre wheelset, and also a 33 is lot easier to keep running as it doesn't have canon tubes, but plain TM suspension bearings.

 

There is some conjecture that the levels of maintenance 33s were subjected to by the southern region were particularly higher than other classes.

 

26s in there latter days were getting very difficult to keep running, body rot was catching up on them and there were a few last gasp bodges to try and slow it down, the vast majority of them were also pretty much on knackered tyres by the time they were up for the chop.

 

Originally 26s were supposed to last until the year 2000 there simplicity contributing greatly to their reliability, but a combination of uk freight dissapearing up its own backside and sprinterisation put an end to this early, they survived this long because they were at the sweet spot of the 6lda sulzer being in its ideal power-band - (ie no intercoolers), and the CP electricals being pretty robust when it comes to abuse!

 

when 33s did make it to scotland....the job they were being asked to do was totally unsuited to them....shunting....lots of shutdowns and restarts...and 33s are EP start machines....which when it comes to batteries will find the slightest weakness!

Edited December 2, 2019 by pheaton

[Rugd1022]

As a secondman at Stonebridge Park in early '83 we had 31 321 arrive one morning for crew training as replacement for the much loved 25s, I remember being quite chuffed at having it on the Watford and Bletchley trips one week, but by the end of the week the driver and I had both decided we preferred the 25s on these jobs. Although comfortable, so long as the doors and windows were shut properly, they didn't have the same finesses for shunting as the 25s. Moving to Old Oak a few months later I found myself on 31s daily, for the most part the OOC batch were really well looked after 9particularly the two skinhead twins 31 117 and 31 121) but we had a spate of failures with two or three of them and one which caught fire twice when I was on it (perhaps I was jinxed!). As Dave-exOC said, they did good work on the 'ups and downs' between OOC and Padd but the odd one did struggle up the E&C flyover on anything but a dry rail. On one occasion, with 31 414 we had to set back into the carriage sidings to have another go with nine Mk1s on. It was easier in the down direction as you could give it some power before Westbopurne Park and go flying over the top, but not so fast that you could stop at the bottom of the bank on the other side. The week after 50 041 derailed at Padd with the sleeper in November '83 I was on ballast turns in the station on 31 124 for several nights on the trot with the engine kept running continuously, by the end of the week the cabs were like ovens - very toasty!

 

I left OOC in '85 and then didn't get on another 31 until just a few years ago, I was conducting a SERCO man from New St to Didcot and back and had a go for art of the journey, it certainly made a nice change from the daily dose of 66s.

Edited December 2, 2019 by Rugd1022

[The Johnster]

7 hours ago, Foden said:

Interesting, you hear largely favourable stories of how diesel hydraulics performed on the Western region. It would appear from the outside looking in that the classes were (for the most part) well designed, good performers, stood up rather well to the rigours of the work they were asked to do (certainly no worse than many other early pilot DE locos), and generally looked upon favourably by the crews that worked and maintained them.

 

So unless, with respect, many of these recollections are nostalgic memories through maybe slightly rose tinted glasses, one wonders why BR were so adamant not to take the diesel hydraulic principle any further?

 

Politics? Expense? Personal favouritism at board level?

My recollections of them as a freight guard at Canton in the 70s does not fully chime with this.  I had comparatively little experience with Warships or 22s, but men who had signed them at Gloucester or Bristol commented that the 22s were gutless and unreliable, that the Warships were good until they’d been a few weeks in service and been thrashed a bit, after which they went off the boil, and had a reliability question over them.  Westerns had an appalling ride as a vicious vibration set in between 50 and 60mph, just the speed range you spent a lot of time sitting at working air braked freight trains.  The Hymeks were universally liked.

 

Westerns were horrible things to climb on to or off from; overhanging steps covered in ice in the winter, handrails inset into the bodyside by some stylist who never had to try to grab the handrail of a moving loco wearing big rubber gloves, and if you did manage to get up the steps you had to negotiate a series of narrow, dark, claustrophobic internal corridors  that smelled of diesel to eventually access the cab; you were essentially in the engine room!

 

The cabs on all the WR hydraulics were very well sound and draught proof, and that stylist mentioned earlier had clearly been let loose on them, to better effect. Rows of warning and indicator lights in futuristic looking cowls that tipped backwards for bulb replacement faced the driver across the desk and the power handle was styled as well; it all looked a bit Thunderbirds/Bond Villain’s Lair.  This emphasised the point that steam had gone and The Future was here, and contrasted strongly with the agricultural look of the cab interiors of Derby’s Type 2s and English Electric’s products.  The feeling was that this was something very high tech, clinical surfaces and lots of lights and dials.  

 

The Western’s cab could be like an oven if the sun shone through those big windows, and the sliding side windows could be draughty if the loco was not in generally good condition, and some of them got very rough towards the end.  

 

The rapid demise of the hydraulics was not, in my view, due to anything as interesting as politics, expense, or personal favouritism.  Their genesis was highly bound up with inter-regional politics and is often viewed as the last gasp of Great Westernism, but the were doomed by purely practical operational matters as much as by the traction plan; unreliability and lack of work for the type 2s, lack of space to put air brake gear in the Warships and Hymeks, and lack of space for ETH and airco equipment in the Westerns.  

[Pandora]

The traction gearing for 90 mph maximum speed may be the problem, a speed  wasted on  unfitted coal train workings of 16T mineral wagons,  if the 31 had been regeared when the engines were replaced for 60 mph running, would the 31 have been as useful as a Scottish BMRCW class 26 for coal trains?

[Bedlington North]

21 hours ago, adb968008 said:

So is a 31...

hence a better comparison.

 

with an EE engine thats 1470hp

against a 33’s 1550hp

vs a 26’s 1160hp

or a 37’s 1750hp

 

obviously weight and axles plays a part, in both cases against the 31.

 

 

 

A 31 is not a Type 3, why do you say it is?

 

A 31 with the EE12SVT was rated at 1470bhp and the Type 2 classification was from 1001 to 1499hp.

[Rivercider]

A selection of comparative maximum loads from some old Freight Train Loads booklets I have.

 

Merehead to Cranmore   Class 25 - 300 tonnes,  Class 31 - 360 tonnes,  Class 37 - 560 tonnes.

 

Severn Tunnel Junction to Acton   Class 25 - 560 tonnes,  Class 31 -  560 tonnes,  Class 37 - 910 tonnes.

 

Bristol to Exeter Riverside (Class 6)   Class 25 - 460 tonnes,  Class 31 - 510 tonnes,  Class 37 -  660 tonnes.

 

cheers

[rogerzilla]

Great stories from former drivers!

[slilley]

11 hours ago, Foden said:

Interesting, you hear largely favourable stories of how diesel hydraulics performed on the Western region. It would appear from the outside looking in that the classes were (for the most part) well designed, good performers, stood up rather well to the rigours of the work they were asked to do (certainly no worse than many other early pilot DE locos), and generally looked upon favourably by the crews that worked and maintained them.

 

So unless, with respect, many of these recollections are nostalgic memories through maybe slightly rose tinted glasses, one wonders why BR were so adamant not to take the diesel hydraulic principle any further?

 

Politics? Expense? Personal favouritism at board level?

The reasons are all contained in a 1965 BR report which compared electric and hydraulic transmission. 

 

It was covered in Class 47 50 Years of Locomotive History.

 

Here is the relevant section.

 

The Type 4 diesel-electric and diesel-hydraulic comparison

In August 1965, the CE (T&RS) published a detailed comparison between diesel-electric and diesel-hydraulic traction. At the time of the report, BR had 2,315 diesel-electric and 358 diesel-hydraulic locomotives in traffic. In the Type 4 power range the comparison was made between the Brush Type 4 and the Swindon/Crewe-built 2,700hp C-C diesel-hydraulic ‘Western’ class. Several categories were covered, including first cost, performance, efficiency, availability, types of defects and casualty rates. As neither class had yet gone through a complete repair cycle, it was not possible to compare maintenance costs.

   Both Type 4 classes had undergone performance and efficiency tests. In the case of the Brush Type 4s, the performance data gathered from No D1500’s tests on the Western Region in November 1962 was used. The ‘Western’ used in comparison was No D1029, the last of its class to enter service, and it had undergone extensive road testing during 1964. In its tests, No D1500 produced a maximum tractive effort of 71,700lb at 6.5 mph, equating to 28.1% of the locomotive’s weight. The ‘Western’ reached a slightly lower maximum of 65,000lb at 4 mph, corresponding to 28% of the overall locomotive weight. These figures were recorded in normal rail conditions, with no wheelslip. It was noted that in more difficult conditions, the diesel-hydraulic was usually more sure-footed as any wheelslip was more easily corrected by torque transfer cardan shafts.  The three axles on the diesel-hydraulic being coupled together gave it the key advantage over the diesel-electric, where each axle was individually powered. Unsurprisingly, greater use of the anti-slip brake was needed with the Brush Type 4 in difficult conditions compared to the diesel-hydraulic.

   No D1500 was able to maintain maximum rail horsepower at an almost constant 2,250hp between 30mph and 80mph, the point at which the main generator unloaded.  The ‘Western’ by comparison only reached maximum engine speed of 1,500rpm at a train speed of 55 mph. Fuel consumption at full power was similar for both locomotives. No D1029’s fuel consumption was 960lb per hour with No D1500’s slightly higher at 1025lb per hour. To put this into context, an Eastern Region report from November 1965 on locomotive costs calculated that the fuel consumption of a Brush Type 4 with the steam heating equipment in use was around 1.35 gallons per mile.

   The report also compared other factors such as build cost, availability and miles per casualty. The average build cost of a Brush Type 4 was £125,000 compared to £136,000 for the ‘Western’. The Brush Type 4 compared favourably in terms of availability. Since the first example had entered service in September 1962, their average availability had been calculated at 85.2%, compared to 76.6% for the diesel-hydraulic Type 4s. Availability over a 40-week period in 1964 was 86.1% for the Brush Type 4, with the ‘Western’ managing 64.3%. The miles per casualty statistics also favoured the diesel-electric, with the Brush Type 4s achieving 11,000 miles per casualty compared to the 8,500 miles of the diesel-hydraulics.

   The casualty statistics for the two locomotive types over the 20 weeks between 16 May and 3 October 1964 were analysed and divided into three categories: engines, transmission, and electrical equipment. The Brush Type 4 had lower average casualty figures for both the engine and transmission categories, with the ‘Western’ faring slightly better in the third category of electrical equipment. Overall, the average number of casualties per locomotive (174 locomotives recording 240 casualties) for the Brush Type 4s was 1.34. The ‘Westerns’ by comparison fared less well, and averaged 1.75 (74 locomotives recording 129 casualties).

   The report’s principal conclusion was that diesel-electric locomotives powered by medium speed engines had proved to be less costly to build and more reliable than diesel-hydraulic locomotives equipped with high speed engines. These findings reinforced BR’s earlier decision that future diesel locomotive types would feature electric, rather than hydraulic, transmission.