Class 31 diesel

Diesel motive power and operations in Southern Africa
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Dylan Knott
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Joined: 17 Aug 2007, 19:44
Location: Cape Town

Class 31 diesel

Post by Dylan Knott »

Can someone please indicate what the axle loading of a class 31 diese-electric locomotive is?

Can this locomotive operate on the Bellville - Caledon line, which has a maximum axle loading of 18.5 tons?

Cheers

Dylan
Kevin Wilson-Smith

Re: Class 31 diesel

Post by Kevin Wilson-Smith »

Dylan - generally the weigh will vary a a bit from spec.

Class 31's are General Electric U12B's in essence, but the version for SAR had a different weight to the US U12B.

SAR's version panned in at 74,000 kg average weight, but more of interest in relation to your question is the maximum all up (fully fueled etc) weight which is 75,6002 kg.

Given that the 31's have 4 axles, this gives an axle loading of 18,900 kg. Converted to tons, this gives

18.9 metric tons (normally "tonnes")
18.6 long tons (i.e. imperial tons)
20.8 short tons

Assuming the ton specification for the line you mention is in long tons (it must be - your reference is unlikely to be short tons, and it probably would have said "tonnes" if they were metric) - this would mean the answer to your question is NO - they would theoretically be too heavy by 100 kgs for the line.

I have given you the numbers - but I cannot comment really on whether, given the above figures, safe operation would still be possible on the weight of line you mention.

Perhaps someone else can comment here? What are the recommended safety margins?
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Dylan Knott
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Joined: 17 Aug 2007, 19:44
Location: Cape Town

Re: Class 31 diesel

Post by Dylan Knott »

They have been used on Malmesbury line which has max axle loading of 18.5 and yet loco is 18.9
Kevin Wilson-Smith

Re: Class 31 diesel

Post by Kevin Wilson-Smith »

Average weight of 74,000 kgs gives an axle loading of exactly 18,500 kgs.

I do not know if this means anything really though. Just playing with numbers?

We probably need someone to advise how the decisions are made, what safety margins apply, etc. I have not the foggiest!

Mike? Nathan?
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Dylan Knott
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Joined: 17 Aug 2007, 19:44
Location: Cape Town

Re: Class 31 diesel

Post by Dylan Knott »

TFR Bellville don't know and we are still waiting (2 months) for them to find out. I know Waterval Boven have a privately owned class 31.

Reckon if it runs with half tank diesel its within loading gauge.
Kevin Wilson-Smith

Re: Class 31 diesel

Post by Kevin Wilson-Smith »

Maybe even with a full tank - everything I have looked at says "average" weights -and then there is the max weight. None of my references indicate what an average weight compromises of - does it include fuel?

Why did the weights vary? What mods applied? Or what else? !!!!

Waterfal Boven do have a nice 31 - I took some pics (not too good) some time ago which I will dog out and post. One of my favorite engines!

Who has the 31 you refer to? Do you have some pics?
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Dylan Knott
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Joined: 17 Aug 2007, 19:44
Location: Cape Town

Re: Class 31 diesel

Post by Dylan Knott »

2 stored at Germiston.
3 operational REGM owned by Sheltam
2 stored at Bellville TFHP. One is in reasonable condition, but the other stripped.
Kevin Wilson-Smith

Re: Class 31 diesel

Post by Kevin Wilson-Smith »

Thanks...
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John Ashworth
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Re: Class 31 diesel

Post by John Ashworth »

Kevin, do post those pics when you get the chance. I get a bit bored with US diesels, which all look the same to me apart from the colour schemes, but I do like some of the more interesting diesels from elsewhere, especially older ones.
Image
Kevin Wilson-Smith

Re: Class 31 diesel

Post by Kevin Wilson-Smith »

Found and scanned them. Here they are...

http://www.friendsoftherail.com/phpBB2/ ... =143&t=874
Chris Janisch
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Joined: 25 Jan 2007, 13:10
Location: Pretoria, South Africa

Re: Class 31 diesel

Post by Chris Janisch »

According to Charlie Lewis, it is very difficult to get accurate information of the condition of line and bridges on the network.This was not the case in the old SAR. The diciest part is bridges, of which there are a good few on the Caledon line. The axle loading is on the limit, but this does not mean the infrastructure can take it. It is therefore highly unlikely that the 31 would be let onto the Caledon line, unless the Section Manager approves it.
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