Unpowered axles on older diesel classes

[Magdalia]

Ok, how were they constructed?

The Deltics a Symposium says this about the prototype:

In design and construction the prototype Deltic was not, in fact, all that remarkable except for the engines. The steel superstructure was a welded one piece load bearing structure already used for several export designs.

Webb's English Electric Main Line Diesel Locomotives of British Rail says this about the EE Type 4s:

The design bears a strong family resemblance to 10203 ... and also a 2000hp type built by English electric for Rhodesia.

The underframe is welded up from rolled steel sections as a single stressed unit.

I'm sure Deltics had a stressed skin bodywork and this was load bearing whereas a lot of early diesels were based on steam technology with strength in the frame and, hence, high weight.

I can't find anything specific in either source to confirm this but I think that you are right.

 

[norbitonflyer]

I went and checked the BR locomotive diagram book and my initial thoughts were correct - there was no weight saving from ETH conversion and indeed the ETH-fitted /1s are heavier than the /0s.

Did they have to be ballasted to prevent uneven weight distribution and/or riding too high on the suspension?

== Doublepost prevention - post automatically merged: 23 Feb 2025 ==

There is nothing much odd with the EE type 4 design, it is where the technology was in 1955.

It was essentially the SR 10203 in a bonnetted body, that was to become the EE norm for the next decade (see also classes 23 and 37) - possibly with a view to export, as the arrangment was favoured overseas at the time)

 

[hexagon789]

Did they have to be ballasted to prevent uneven weight distribution and/or riding too high on the suspension?

That's what I wondered.

 

[norbitonflyer]

I’ve always thought that DP2 was the class that got away, given it could match Deltic performance and would have had some standardisation with the EE Type 3s. Surely a better option than the Brush Type 4s?

DP2 was productionised as the Class 50 - the engine from the wreck of DP2 was even salvaged and used in the class 50 fleet. And they did have standardisation - the bogies in particular were common to classes 37, 50 and 55. The different appearance of the class 50s was the result of the Design Panel requirements - it is no coincidence that "Falcon" "Lion" and classes 47 and 50* all look very similar - and of course the class 56, which used the same bodyshell tooling as the 47, but with a further uprated version of the engine in classes 40 and 50 - the most noticeable difference being the position of the headcode boxes on the class 50. Indeed, DP2 did not comply with the specification set by the Design Panel for the three prototypes (DP2, Falcon and Lion), but simply used the Deltic bodyshell design for which they already had the tooling.

In the "Symposium" book mentioned in previoius posts there is a line drawing of a "Super Deltic" of 4,400hp using two turbocharged versions of the 18 cylinder Deltic engine (not so far-fetched - a turbocharged Deltic engine altready existed in the Baby Deltics) and the bodyshell for that closely resembles a Class 50.

*also the otherwise unrelated classes 35 and 87

 

[Gloster]

I read that the 44 had to be ballasted with concrete once their boilers were removed in order to ensure even weight distribution.

 

[Richard Scott]

I went and checked the BR locomotive diagram book and my initial thoughts were correct - there was no weight saving from ETH conversion and indeed the ETH-fitted /1s are heavier than the /0s.

No they aren't. A 45/0 is 138 tonnes with RA7 and a 45/1 is 135 tonnes with RA6.

 

[The Crab]

Adding more traction motors and their associated equipment would have further increased the overall weight and, crucially, the loco's axle load.
The whole rationale of the unpowered axles, was to bring the loco axle load down to that permissible by the Civil Engineer, for the loco's specified RA (Route Availability).

In the cases of (what became) classes 31, 40, 44, 45 and 46, the locos would have exceeded the maximum allowable axle load for UK railways of that time.
Sulzer Type 2 (class 24), when initially built, needed remedial work to reduce weight and lessen their axle load, before they gained approval into BR(LMR) traffic.

Didn't the Sulzer 2s have their boilers removed to reduce axle weight when they were sent on loan to the Southern Region about 1959(?)?

 

[Sun Chariot]

Didn't the Sulzer 2s have their boilers removed to reduce axle weight when they were sent on loan to the Southern Region about 1959(?)?

That's right, yes

 

[norbitonflyer]

Didn't the Sulzer 2s have their boilers removed to reduce axle weight when they were sent on loan to the Southern Region about 1959(?)?

I thoughth they were sent to the Southern specifically to provide steam heat on class 33-hauled trains, when there was still some steam-heat stock around, or was that later?

 

[Sun Chariot]

I thoughth they were sent to the Southern specifically to provide steam heat on class 33-hauled trains, when there was still some steam-heat stock around, or was that later?

This extract from the linked page of Derby Sulzers:

1958 1959 class 24, class 25, class 45 information history

The loaned Southern Region' Type 2s now numbered fifteen but had been subdivided into two distinct groups, those with their boilers removed (D5002 - 5006), and those still as built (D5000/01/07-14).

Eastern section:
All were banned between Tonbridge and Bo Peep Junction, Middle Junction to Sheerness on Sea and from Tilmanstone and Tenderten branches. The heavier machines were also banned from the Allhallows, Grain, Hawkhurst and Westerham branches.
Oddly, all were allowed down the steeply graded Folkestone Harbour branch.

Central section:
The only restrictions applied to the heavier machines, banned between Three Bridges and East Grinstead and onto Ashurst Junction and the Heathfield line

Western Section:
All were banned from Bodmin North, Barnstaple, Ilfracombe, Callington, Halwill, Hayling Island, Lyme Regis and Torrington branches.