BR Type 3s - Regional Preferences

[Cowley]

No, don't think so. Not sure when the cement started runing, but ISTR it was running in 1961, and the 33s were used long after the 24s had been returned to the LMR (which I think was in 1962). The cement trains were also heavy - two 33s had something like 700 HP more than 2 x 24s - and I'm sure they needed that power to keep to decent timings on the GN.

Ah I didn’t realise that the 24s had gone back but they were still using the 33s on the cement. Interesting stuff (coming on here with your rational arguments and experience, pah ).
I think I read somewhere that the SR had about 15-16 class 24s on loan and that sometimes they were paired up with the 33s on heavier trains in winter with the 24 providing heat.

 

[Grumpy]

BR only really needed to order one class of diesel for the modernisation plan-the class 33. It had high route availability, electric heating, dual controls etc. It had adequate power for most requirements and could simply have been run in multiple where more power was necessary. Just think of the savings in staff training, stock of spares, low production costs from a long production run etc.

 

[70014IronDuke]

BR only really needed to order one class of diesel for the modernisation plan-the class 33. It had high route availability, electric heating, dual controls etc. It had adequate power for most requirements and could simply have been run in multiple where more power was necessary. Just think of the savings in staff training, stock of spares, low production costs from a long production run etc.

Brilliant idea! It's shocking nobody ever thought of that at the time, really.
Pity the passengers in the 15,000 carriages that had only steam heat though

 

[randyrippley]

Probably worth bearing in mind that BRCW went out of business in 1962, once production of the 27s and 33s was completed, so when it came to further orders of diesel-electric Type 3s, the 37 was the only game in town - 190 of the 308 Class 37s eventually built were ordered in July 1962 and 1964.

BRCW didn't go out of business: they simply predicted the hiatus of orders in the mid-60s due to Beeching and shut down their manufacturing. They remained in business as a renamed publicly quoted investment company. Still in business now, but I can't remember the name

 

[Sod]

Probably worth bearing in mind that BRCW went out of business in 1962, once production of the 27s and 33s was completed, so when it came to further orders of diesel-electric Type 3s, the 37 was the only game in town - 190 of the 308 Class 37s eventually built were ordered in July 1962 and 1964.

I seem to recall that it was the shrinking-down of the class 33s to the Hastings gauge of the "Slim-Jims" that brought about the demise of the Birmingham RCW company, as it was an unexpectedly costly engineering exercise to amortise across only a handful of locomotives. The fact that there is still such a high proportion of the total build of class 33s in active service (across both mainline and heritage railways) is testament to what an intelligent design the Southern specified all those years ago.

 

[randyrippley]

Its worth seeing what the Derby Sulzers site has to say about the decision to purchase the 33
https://www.derbysulzers.com/class33.html

"
In placing the specifications for the Type 3, the Southern Region had a very clear idea of what was required, including some features which were outside of the BTC's specifications. These requirements included:

Haulage of 700 ton freight trains on ruling gradients of 1 in 70
Haulage of 375 ton passenger & van trains over electrified and non-electrified routes
Fitting of equipment to provide electric train heating
Ability to haul electric multiple unit stock at normal speeds over all routes in times of emergency
Maximum service speed of 85mph
Ability to work vacuum & air-braked rolling stock
A wide route availability

The BTC Class 3 specification included two contenders, the 1,750bhp 105 ton Co-Co 12 cylinder equipped offering from English Electric or the 1,550bhp 76 ton Bo-Bo 8 cylinder equipped offering from BRCW. The BTC were in favour of the English Electric design, wishing to make it a standard design, but the Southern Region favoured the BRCW design from the outset on the grounds of weight & cost. It also offered the requested dual braking equipment, the electric train heating function and had a better route availability. The BTC held out for a maximum speed of 80mph but agreed to the fitting of dual braking equipment, an awkward about face following their recent decision to generally retain the vacuum brake as standard."

Its also interesting to see how widespread the use of the 26/27 fleet was outside of Scotland
https://www.derbysulzers.com/class26.html

 

[Grumpy]

Pity the passengers in the 15,000 carriages that had only steam heat though

The number of carriages at the beginning of the modernisation plan would be considerably reduced as a result of new EMU/DMU schemes under the plan and the resulst of Dr. B. The remaining carriages would need to be dual heated to allow haulage by electric locos. Adding weight and cost to diesel locos to provide steam heating-with consequent maintenance cost and reliability problems- was bonkers.

 

[jimm]

BRCW didn't go out of business: they simply predicted the hiatus of orders in the mid-60s due to Beeching and shut down their manufacturing. They remained in business as a renamed publicly quoted investment company. Still in business now, but I can't remember the name

Hiatus, or the fact that while BRCW's Lion proved the single-engine Type 4 Co-Co diesel-electric concept, as opposed to Brush's twin-engine Falcon design, BR preferred to go with Brush as the builder for what would eventually be the 512-stong Class 47, with production lasting until 1968? And the July 1962 order for 100 more Class 37s from English Electric, followed in 1964 by orders for 90 more, with production running until 1965?

Had BRCW won any of that work, they would have been busy for a good few years to come, though it's not hard to see why 37s would be preferred for coal traffic in South Wales and elsewhere, instead of a lighter Bo-Bo design, whether the 33 or the Hymek.

 

[Grumpy]

Had BRCW won any of that work, they would have been busy for a good few years to come, though it's not hard to see why 37s would be preferred for coal traffic in South Wales and elsewhere, instead of a lighter Bo-Bo design, whether the 33 or the Hymek.

Class 33's seemed to manage with coal in Kent. Also with the heavy cement trains to York and oil trains to Bromford Bridge. I had always assumed the South Wales coal trains ran predominantly downhill when loaded so the need was perhaps to attach a brake tender when needed, rather than have to lug around the extra 30 tons on a class 37 forever.

 

[Taunton]

Hymeks getting a bit left behind here ...

In fact they were an extraordinarily capable class. When new in 1961-2 D7024-39 were sent to Cardiff and dieselised the main South Wales to London expresses for the first year or so, until more Westerns were available. You would not believe the speed they still had coming over the top of the long 1 in 100 climb from the bottom of the Severn Tunnel all the way up to Patchway station with maybe 12 on, these were the heaviest expresses on the WR. They had been specified as Hall replacements but got put on King work and timings.

There were always one or two around Taunton during the day, not on any mainline passenger service but on odd jobs. Overnight however, when the WofE line got even busier with freight (long lost days) their unique ringing high-pitched exhaust noise could be heard resonating across the town as they slowly opened up through the station.

 

[ac6000cw]

Hymeks getting a bit left behind here ...

In fact they were an extraordinarily capable class. When new in 1961-2 D7024-39 were sent to Cardiff and dieselised the main South Wales to London expresses for the first year or so, until more Westerns were available. You would not believe the speed they still had coming over the top of the long 1 in 100 climb from the bottom of the Severn Tunnel all the way up to Patchway station with maybe 12 on, these were the heaviest expresses on the WR. They had been specified as Hall replacements but got put on King work and timings.

I never managed to see, let alone ride behind, a Hymek in BR service (they were mostly withdrawn by the time my railway interest started), but as you imply the 'hydraulics' generally were very good performers (ignoring the early NBL-built junk...). In particular the mechanical coupling of the axles in a bogie made them less prone to wheelslip, as an individual axle can't slip relative to the others - the Achilles Heel of DC-drive diesel-electrics, only fixed when AC-drives/DC-sepex appeared. I think that relative to its weight, a Western had more starting tractive effort than anything else on BR at the time - 66,700 lbf (297 kN) for 110 tonne loco weight. A 76 tonne Hymek managed 46,600 lbf (207.3 kN), a 102 tonne class 37 55,500 lbf (247 kN) with the benefit of two more axles, and a 75 tonne class 33 was 45,000 lbf (200 kN).

BR only really needed to order one class of diesel for the modernisation plan-the class 33. It had high route availability, electric heating, dual controls etc. It had adequate power for most requirements and could simply have been run in multiple where more power was necessary. Just think of the savings in staff training, stock of spares, low production costs from a long production run etc.

As for double-heading with 2 x Cl.33 instead of a Type-5 on passenger trains - it's more expensive (more locos, more dead weight to lug around) and they take up more space at terminal stations. You could regard the Warships/Westerns/Deltics as two locos in one body anyway. And incidentally, I think the practice of using multiple diesels on a train really started in the early USA diesel era, when all that EMD (and others) offered for freight were relatively low-powered (around 1300-1500hp) locos, which *had* to be used in multiple to match the power of the large steam locos hitherto used to haul the trains (the biggest US steam power was in the 5000-6000 drawbar hp range, which was why the 1939 EMD 'FT' demonstrator set was comprised of 4 x 1350hp 'units', to match 'big steam' power capability whilst pretending to be a single loco from the point of view of union rules about crewing).

 

[Taunton]

the mechanical coupling of the axles in a bogie made them less prone to wheelslip, as an individual axle can't slip relative to the others

Curiously the only diesels I can recollect audibly slipping at all were the Warships. I know they were in my locality, but in heavy rain on several occasions I remember them slipping trying to start westbound from Taunton. Probably the front end only.

Not the Hymeks though.

 

[jimm]

Class 33's seemed to manage with coal in Kent. Also with the heavy cement trains to York and oil trains to Bromford Bridge. I had always assumed the South Wales coal trains ran predominantly downhill when loaded so the need was perhaps to attach a brake tender when needed, rather than have to lug around the extra 30 tons on a class 37 forever.

Kent isn't exactly noted for stiff gradients... and the 37 has a route availability of 5, as opposed to 6 for 33s, so probably a benefit on old or iffy track on colliery branches and in sidings etc.

The cement and oil trains to York and Birmingham you mention were often double-headed, whereas single Class 37s were trusted to work some hefty loads down the Welsh Valleys. I suspect a 100-ton loco with six braked axles would be preferred by drivers to 75 tons and four braked axles in such situations - not forgetting the accountants who presumably preferred use of a single loco to double-heading...

 

[randyrippley]

Curiously the only diesels I can recollect audibly slipping at all were the Warships. I know they were in my locality, but in heavy rain on several occasions I remember them slipping trying to start westbound from Taunton. Probably the front end only.

Not the Hymeks though.

Were the two bogies on a Hymek locked through the transmission? If so that would explain your comment. The bogies on the Warships were independently powered: one from each diesel?

 

[36270k]

One factor in the success of the Class 33 was that maintenance standards were higher on the Southern than on the other regions.
Visiting Class 47's from the WR and LMR were often filthy with Oil leaks everywhere.

 

[randyrippley]

Hiatus, or the fact that while BRCW's Lion proved the single-engine Type 4 Co-Co diesel-electric concept, as opposed to Brush's twin-engine Falcon design, BR preferred to go with Brush as the builder for what would eventually be the 512-stong Class 47, with production lasting until 1968? And the July 1962 order for 100 more Class 37s from English Electric, followed in 1964 by orders for 90 more, with production running until 1965?

Had BRCW won any of that work, they would have been busy for a good few years to come, though it's not hard to see why 37s would be preferred for coal traffic in South Wales and elsewhere, instead of a lighter Bo-Bo design, whether the 33 or the Hymek.

They wouldn't have won those orders: they were too small to build the numbers required.
By 1961-62 it was becoming clear that BR was standardising on large numbers of a a few classes, and BRCW didn't have the production capacity to scale up to what was needed. Thats why the 25 became the standard type 2, not the 27. If they had scaled up, it was clear that by 1966 that increased production would have become redundant: the looming 10 year order gap for diesels between the end of class 47 production and the beginning of 56 production was obvious. BR had too many locomotives, reducing orders, and the smaller manufacturers were going to get squeezed out. The writing was on the wall with what happened with the bankruptcy of North British - BRCW decided to prevent that happening to them, and changed the direction of the company.
As for "Lion" getting a production contract, that was a total non-starter. Partially built in glass fibre with question marks over body durability, and allegedly poor engineroom access. But by the time it was built and on trial, BRCW had already lost interest in locomotive production anyway: the story goes that Sulzer tried to keep the loco in service on their own, with little or no support from BRCW engineers until it finally failed beyond redemtion

 

[ac6000cw]

Curiously the only diesels I can recollect audibly slipping at all were the Warships. I know they were in my locality, but in heavy rain on several occasions I remember them slipping trying to start westbound from Taunton. Probably the front end only.

Not the Hymeks though.

The Hymeks had a single engine and 'Mekydro' transmission (driving all four axles), so that in theory that should be even better for wheelslip prevention since all axles are coupled together, not just within each bogie.

(Fantasy thought: I wonder if you could have squeezed the engines and transmissions of two Hymeks into a single UK size C-C loco, to create a 'super' Western to surpass a Deltic?
Krauss-Maffei did something very similar in 1961 for the American market...)

 

[randyrippley]

.........Fantasy thought: I wonder if you could have squeezed the engines and transmissions of two Hymeks into a single UK size C-C loco, to create a 'super' Western to surpass a Deltic?
Krauss-Maffei did something very similar in 1961 for the American market...)

I've read that it was considered, but felt to be impossible within the UK loading gauge. Somewhere online on a Bristol-Siddeley fan's website that I haven't a link for....

 

[Ash Bridge]

The Hymeks had a single engine and 'Mekydro' transmission (driving all four axles), so that in theory that should be even better for wheelslip prevention since all axles are coupled together, not just within each bogie.

(Fantasy thought: I wonder if you could have squeezed the engines and transmissions of two Hymeks into a single UK size C-C loco, to create a 'super' Western to surpass a Deltic?
Krauss-Maffei did something very similar in 1961 for the American market...)

That would certainly have been quite some machine, although surely it would have pushed the overall weight up to around the 120t plus mark?

 

[randyrippley]

That would certainly have been quite some machine, although surely it would have pushed the overall weight up to around the 120t plus mark?

Just under 154 tons
http://sp9010.ncry.org/

 

[Ash Bridge]

Just under 154 tons
http://sp9010.ncry.org/

Hell! That even eclipses the Peaks, with such an axleload I would doubt that a locomotive of that weight could have run anywhere else in Europe perhaps with the exception of Russia?

 

[ac6000cw]

As it would basically be a Western with V16 Maybach engines instead of the V12 version, plus maybe slightly heavier transmissions, I suspect 120-ish tonnes is probably a reasonable guess, especially if it didn't have a steam heating boiler and water tank (but you'd need the water tank space for a bigger fuel tank). That's about the weight of a Class 47. Those K-M freight diesel-hydraulics were relative lightweights in the US - the contemporary six-axle EMD SD24 was about 175 tonnes, and a modern US Siemens 125 mph 'Charger' passenger diesel is 120 tonnes on four axles (gulp!)

 

[Ash Bridge]

As it would basically be a Western with V16 Maybach engines instead of the V12 version, plus maybe slightly heavier transmissions, I suspect 120-ish tonnes is probably a reasonable guess, especially if it didn't have a steam heating boiler and water tank (but you'd need the water tank space for a bigger fuel tank). That's about the weight of a Class 47. Those K-M freight diesel-hydraulics were relative lightweights in the US - the contemporary six-axle EMD SD24 was about 175 tonnes, and a modern US Siemens 125 mph 'Charger' passenger diesel is 120 tonnes on four axles (gulp!)

That last one is enough to make any European railway authority have nightmares lol, don't want to keep so off topic for much longer but whilst on the subject of locomotive weights surely the class 45/46 were the heaviest single unit diesels to operate in Europe if we exclude Russian built stuff, the nearest I think are the Ludmilla's which are similar to a 60 at around the 127-131 tonnes mark.

 

[Spartacus]

As I understand it, the decision to go with Class 73s was essentially because of not enough 37s being available?

The 73s would have been a lot more tunnel friendly too, gauge wise as well as being able run run off the juice. I guess it might be possible for 37s to have been cleared, but I know 73s were.

 

[randyrippley]

Hell! That even eclipses the Peaks, with such an axleload I would doubt that a locomotive of that weight could have run anywhere else in Europe perhaps with the exception of Russia?

I suspect much of the weight comes from it being an underframe / solid chassis "bone" design, not a spaceframe / monocoque.
I've read elsewhere that the abortive UK plan was to put two Hymek engines each rated at 2000bhp into a Western body - however there were doubts it would fit.
Interestingly anecdotally it would seem the MD870 in the Hymek was downrated because the BR "Type" classification didn't allow for a locomotive with a nominal 1920bhp ------neither Type 3 or Type 4, so they reduced the power to make it fit the system

 

[Western Lord]

I've read that it was considered, but felt to be impossible within the UK loading gauge. Somewhere online on a Bristol-Siddeley fan's website that I haven't a link for....

In February 1963 Maybach sent a general arrangement drawing of a 120 ton 4000bhp C-C loco based on a D1000 shell but with MD870 engines set to their UIC rating of 2000bhp and with Mekydro K184 transmissions. This is illustrated in Brian Reed's book Diesel Hydraulic Locomotives of the Western Region, page 86. As Reed relates, the drawing was not even acknowledged by BRB, but soon after designs for 4000bhp diesel-electrics began circulating.

 

[Grumpy]

As for double-heading with 2 x Cl.33 instead of a Type-5 on passenger trains - it's more expensive (more locos, more dead weight to lug around) and they take up more space at terminal stations. .

Just like HST then

 

[30907]

Just like HST then

But much less powerful, and not originally designed for push-pull or sandwich working.

 

[delt1c]

Also remember that the southern region had the requirement that they had to work with other SR traction and their unique MU control system and have electric heat/ETH.
Other regions did not need MU control and required steam heat rather than ETH.

Sorry but in as built condition they were Blue star MU and ETH. The SR MU was fitted later when some were converted for the Bournemouth electrification. The 33 actualy used the class 26 body shell adapted for the larger engine but without the steam heating boiler

 

[Taunton]

As Paxman managed to get 2 x 1,200 12-cyl YJ engines into 78-ton D830 Majestic (overall sound being about an octave higher than the rest of the Warships), 2 x 1,700 should have been well within a 20-ton axleload C-C loco.

The Southern Pacific German hydraulics may have been 154 tons, but not only do US roads expect 25 ton axleloads for adhesion with such substantial trains, they sometimes at rebuilding actually increase the weight with ballast. Additional weights inside the body have comprised both cast concrete blocks, and scrap steel pieces from old locos, welded together!