What Happened to the JVS12Ts?

[45125]

Many of them ended up in trawlers and oil rig supply vessels. Many of the engines had the repairs to the fatigue related cracks in the blocks. When I started as an apprentice in 1975 at least two Mirrlees blocks where round the back of the works at Doncaster.

[BrushVeteran]

Many of the Mirrlees power units were sold as scrap by BR to Alan Finlay of Blackerhill, Barnsley, later to become Hartwood Exports of Hoyland Common. I remember the Blackerhill yard having at least 20 or 30 units in their yard back in 1968-9 ish.

I know one of the MD655 Maybach units out of Falcon ended up in Joe Sykes bus breakers yard at Carlton, Barnsley in 1977 as I tried to find a home for it with one of the preservation groups. I think at the time it was £40 per ton! I have a photo of it somewhere.

Edited April 3, 2020 by BrushVeteran

[WTO]

I have been alerted to this forum and specific exchange via the ‘Mirrlees Memories’ Facebook group (Closed Group open to anyone with Mirrlees background or interests) and decided to make a contribution to this dialogue. I was trained at Mirrlees in the period immediately after Mirrlees and BR parted company.

The JVS12T engines did crack and a repair programme was put in hand to produce modified frames to a Mark 2 version with reinforcing in appropriate places as a short term interim measure whilst a long term Mark 3 frame was developed. The Mark 3 design was a clean sheet of paper exercise and a radical new design was produced. This new design used the same design logic adopted for another order for a larger engine type for the MOD logistics vessels (Sir Galahad, etc) with severe shock loading requirements (with no cracking in service on any of the engines – the last of which were only scrapped within the past decade). In the view of the former Chief Designer this was an overkill exercise for the BR application concerned. I understand that BR had no interest in the Mark 3 frame proposals (having already ordered substantial numbers of replacement engines as we now know!). See Pages 116 to 121 of ‘The Diesel Impact on British Rail’ by R M Tufnell published in 1979 - ISBN 0 85298 438 3

The redundant JVS12T engines were disposed to various organisations including North Lincs Engineering ( a picture exists of numerous engines in a field as purchased by NL) and many went into service in various roles. NL reengineered the sets for new applications but without changing any major components. The NL supplied engines were used for subsequent decades with no issues such as cracks developing into failures. The last NL engine in service was one sold to a scrap merchant on the Channel Islands to drive a metal fragmentation unit which is a very tough duty. The engine lasted for over 40 years in this application and the MD of NL commented ‘Not bad for an engine condemned as scrap by BR!’  It was only at the stage did NL scrap the final remaining engine which had been kept as an insurance policy in case the cracking problem had developed – thus eliminating a perfect piece of kit to permit a conversion of a Class 31 back to a 30.

As a trainee at Mirrlees a visit was organised each month to further our education resulting in visits during my time to the likes of Rolls Royce, English Electric Diesels, Ford Halewood, Fylingdales and British Rail. One of those visits was to BR Crewe where we were shown around by BR apprentices who were quite happy to show us to tell us the ‘full story’ without realising that we were all student and graduate engineers, some with considerable experience and knowledge. We were shown into a former steam workshop that had been converted into a machine shop for repairing diesel engine major components on an industrial scale. We were able to examine in great detail bedplates and frames of all makes and type (except Mirrlees!) which were undergoing a substantial repair exercise with full re-machining. We were told that this was a major issue with the BR diesel fleet at that time. The apprentices were surprised that we knew so much about the things we were viewing! The conclusion of the visit was that many engines in BR use had cracked and not just the Mirrlees J.

 

In reviewing the  BR Diesel Programme there was a rumour that EE were promised a big engine order as compensation for a major order being placed with Sulzer. The Mirrlees J cracking issue would have provided an ideal opportunity for such an order whilst at the same time rationalising on the number of engine makes and types in service. The timing for the replacement engine orders with EE does suggest that this could be the case. The Anson Engine Museum now holds the Mirrlees company records and a few years back an author visited to read the company files in relation to BR and the Mirrlees J,  having also researched the BR records in the National Archive on the  same subject to finally prove this one way or the other.  I haven’t seen anything published so far.

JV12 engines do occasionally turn up and one was offered for preservation in April 2020. If someone is serious in pursuing a conversion back to Class 30 then the best way forward would be via the Mirrlees Memories FB Group and  the Anson Engine Museum http://www.enginemuseum.org/

 

 

[PerthBox]

One of my other interests is Cold War civil defence. In the really excellent book Burlington by Nick Catford there are three photos of the four JVS12 generator sets which were used for standby power at the formerly top secret Corsham Central Government War Headquarters (the 'Burlington' of the title), located in Spring Quarry Corsham next to Box Tunnel. The book notes that the generator sets were installed and commissioned in winter 1961. It doesn't specify where they came from but I think 61 would be a bit early for secondhand units ex class 30 to be available?

Edited June 21, 2020 by PerthBox

[slilley]

Just as an aside to this, Mirrlees had a 12 cylinder engine under development capable of delivering up to 2850hp at 1200 rpm known as the "J Major". Brush even went so far as to design a generator for it with a view to one engine being put in a Brush Type 4 then under construction. The proposal died a death in December 1962 and soon afterwards the Mirrlees engines in the Brusg Type 2s began developing cracks.

 

Simon

Edited June 21, 2020 by slilley

[russ p]

1 hour ago, PerthBox said:

One of my other interests is Cold War civil defence. In the really excellent book Burlington by Nick Catford there are three photos of the four JVS12 generator sets which were used for standby power at the formerly top secret Corsham Central Government War Headquarters (the 'Burlington' of the title), located in Spring Quarry Corsham next to Box Tunnel. The book notes that the generator sets were installed and commissioned in winter 1961. It doesn't specify where they came from but I think 61 would be a bit early for secondhand units ex class 30 to be available?

 

Some bunkers also has the paxman V16 as fitted to class15s. For many years in the late 80s a paxman V16 stood next to the railway at aldwarke junction not sure where that came from or went

[Evertrainz]

WTO, that's a fascinating bit of info there. 

 

Speaking of a JV12, could this be one of those examples? Stated to be a 50-year-old (so late 50s-early 60s) Mirrlees, so might be a JV12, or even a JVS12T? I can't find anymore identifying info on it.

 

 

Edited June 22, 2020 by Evertrainz

[TravisM]

27 minutes ago, Evertrainz said:

WTO, that's a fascinating bit of info there. 

 

Speaking of a JV12, could this be one of those examples? Stated to be a 50-year-old (so late 50s-early 60s) Mirrlees, so might be a JV12, or even a JVS12T? I can't find anymore identifying info on it.

 

 

I’m just a little intrigued as to the power unit as it seems rather large to fit into a BR loco using the mechanics as a scale.  Interesting video though.

[Evertrainz]

On 22/06/2020 at 17:55, jools1959 said:

I’m just a little intrigued as to the power unit as it seems rather large to fit into a BR loco using the mechanics as a scale.  Interesting video though.

 

https://www.youtube.com/watch?v=wYzdert7TMI

 

This video shows off a JV16 and it looks quite similar to the V12 we can see in the startup video, apart from the addition of 2 pairs of cylinders obviously   . Assuming that similar engine product lines shared similar build and casing apart from the number of cylinders (V12 vs V16 vs V8, etc) I think that the startup video actually does showcase a JV12, or maybe a JVS12T. I have no idea what the engines originally looked like but one difference is that the JVS12T was turbocharged I believe? I do wonder what the extra 'S' and 'T' stand for. 

 

EDIT: Apparently not - a quick search for the Battery Point power station reveals that it is actually a Mirrlees KVSS12, attached to Brush alternators.

Edited June 24, 2020 by Evertrainz