D301 Class

[ger711]

Lads,

 

Anyone got any photos of the D Class Shunters other than what few are available online. Just wondering if both side profiles are identical as I might try a Lima Class 08 conversion in the future.

 

Thanks for any help.

 

Ger.

[Mol_PMB]

A little bit of digging in my memory, library and online has produced the following. 

In IRRS Journal No.84, D. Renehan's article on the E class includes an introduction covering some of the earlier diesel shunters in Ireland, including a couple of paragraphs on the D class which provide some useful technical data.  

In 1945, CIE placed an order with Brush Electrical Engineering Company for the supply of engines and electrical equipment for five 0-6-0 diesel-electric shunting and transfer locos. The first was completed in December 1947. 

In the mid-1940s, Brush was primarily an electrical equipment supplier. Brush did not make their own engines, but bought them from several manufacturers: Mirrlees was one of the most common makes used. Brush did not usually make the mechanical parts themselves, these could be subcontracted or left to the customer to build (as with the D class). However, Brush must have had close involvement in the design of the mechanical parts and the interfaces to the engine, generator, motors, transmission, cooler group, controls etc. In 1947, Brush Electrical Engineering Co joined with W. G. Bagnall (a former steam loco builder) so that they could produce complete diesel-electric locomotives including the mechanical parts - however by this time the D301 class were already under construction.

Brush's main-line type 2 loco for British Railways was the Class 30, which had a Mirrlees engine originally. Later they were re-engined with English Electric engines and re-classified Class 31. They did not build any 0-6-0 shunters for British Railways, and just one 0-4-0.

However, Brush also produced many locos for industrial and export customers, often with mechanical parts from Bagnall, though other firms such as Hudswell Clarke and Beyer Peacock were sometimes used. In the UK, many Brush locos were built for steelworks, and these included 0-4-0, 0-6-0 and Bo-Bo shunters, all diesel electrics and mostly with Mirrlees engines. I have encountered the 0-4-0 and Bo-Bo variants myself at Port Talbot (I did some work for the railway there a few years back). The Bo-Bos were still in use until the recent closure of the blast furnaces, though they had been re-engined. Here's one of Gordon Edgar's photos:

The Bo-Bo doesn't look to have much in common with the D301 class. But the 0-6-0 variant of the Brush-Bagnall-Mirrlees locos looked like this (photo from Hugh Llewelyn on Flickr):

Compare the bodywork to a D301 class, especially the bonnet side doors and louvres, and you'll see a very clear link to the D301 class.

Inchicore built the mechanical parts for the D301 (rather than Bagnall) but I suspect they used many details from the Brush design. Dimensional changes would have been needed for the wider track gauge. The UK steelworks locos were too big for the British Railways loading gauge and might have needed slimming down a bit to fit the CIE loading gauge too.

From D. Renehan's article, the engine in the D class was a Mirrlees TLDT6 vertical 6-cylinder of 487bhp at 710rpm. This drove a Brush 290kW dc traction generator and a 10kW auxiliary generator. There were Brush nose-suspended traction motors on the leading and trailing axles. 

The arrangement of the steelworks 0-6-0 locos was very similar, with subtly different engine variants (Mirrlees TLT6 and TLST-6). 

The 487bhp engine power was significantly greater than the equivalent English Electric 350hp locos, but may not have been fully utilised as the total generator rating of the Brush design was only 400hp.

 

 

Now to the dimensions, here is a CIE diagram of the D301 class posted by @BosKonay

The drawing has few dimensions. Based on those which are shown, I estimate the image is to a scale of 0.0353 feet per pixel.

Using that to scale other measurements:

• Length over buffers:  28'9" (should be 29'0" according to IRT&T data)
• Wheel diameter: 4'0" (should be 4'0" according to IRT&T data)
• Length over headstocks: 25'9"
• Wheelbase: 11'8" (5'9" + 5'11")
• Front overhang buffer-wheelset 8'3"
• Rear overhang buffer-wheelset 8'9"
• Width over cabsides: 9'0"
• Width over bonnet: 6'6"
• Height to cab roof: 13'1"

Scaling off drawings can introduce inaccuracies, as can copying and scanning. I'm not claiming these figures are perfect but they should be reasonably close, perhaps +-3" or 1mm in model form.

It's probably most useful to compare those to the LMS class 11 (BR 12033-12138) and the BR class 08, since those are readily available in model form. The LNER type (BR 15000-15004) is also an interesting comparator. Data from 'The Diesel Shunter' (Marsden)

 

Now, given the potential inaccuracies of the scaling process, many of these dimensions are acceptably close.

Note that the wheel diameter of the Class 08 is larger than the rest. In this respect, the Heljan class 11 model might be a preferred starting point for some. 

The D301 is also slightly wider and taller than the other types, with that high curved roof. I note that @Auto-Train Original has already dealt with this on his model - good work!

I haven't considered the accuracy of the available models of these prototypes - they may not be spot-on themselves.

[DJ Dangerous]

I'd put my kidney down that we'll see a D301 Class from A/S at some stage...

The only quandary is whether it will be O Gauge, OO Gauge, or both.

[Mayner]

I

2 hours ago, Mol_PMB said:

A little bit of digging in my memory, library and online has produced the following. 

In IRRS Journal No.84, D. Renehan's article on the E class includes an introduction covering some of the earlier diesel shunters in Ireland, including a couple of paragraphs on the D class which provide some useful technical data.  

In 1945, CIE placed an order with Brush Electrical Engineering Company for the supply of engines and electrical equipment for five 0-6-0 diesel-electric shunting and transfer locos. The first was completed in December 1947. 

In the mid-1940s, Brush was primarily an electrical equipment supplier. Brush did not make their own engines, but bought them from several manufacturers: Mirrlees was one of the most common makes used. Brush did not usually make the mechanical parts themselves, these could be subcontracted or left to the customer to build (as with the D class). However, Brush must have had close involvement in the design of the mechanical parts and the interfaces to the engine, generator, motors, transmission, cooler group, controls etc. In 1947, Brush Electrical Engineering Co joined with W. G. Bagnall (a former steam loco builder) so that they could produce complete diesel-electric locomotives including the mechanical parts - however by this time the D301 class were already under construction.

 

There is an IRRS Journal Article (possibly early 1980s) on CIEs First Diesel Programme in 1945  which included a proposal for a "Luxury Tourist Train" and diesel locos. The original expectation appears to be that Bush and other potential suppliers would supply the Tourist Train and locos complete, but were unable to supply a complete tourist train or locos because of material shortages and the lack of workshop capacity as Britain was recovering from the War

The Tourist Train and proposed single cabbed diesel loco may have been inspired by American rather the British practice as the first CIE Chairman and proponent of dieselisation A P Reynolds visited the States on a fact-finding mission on diesel traction during WW2 while in a similar role with DUTC.

Interestingly CIE shifted to Sulzer engines in combination with Metrovickers Electrical equipment for the two Mixed Traffic locomotives and the six proposed twin engined Express Locos before being forced to cancel the dieselisation policy following a change of Government and Nationalisation of CIE

Edited 4 hours ago by Mayner

[leslie10646]

Just for the record, the article with john refers to is "CIE: First Diesel Programme" by JJ Leckey which you'll find in Journal No.86 pages 275 - 277.

The same Journal has a substantial article by Dan Renehan on CIE's Sulzer locos