Telling apart first-gen DMUs

[MK Tom]

This is probably something that's been done before but I wonder if anyone could help me in finding ways to identify a few classes of first gen DMU? I know stuff like high/low density layouts and stuff like that, but there are a few classes I still can't tell apart:

107/108/114/125 - some 108s don't have headcode boxes but those that do, how do you tell them from 107s? The ones that don't, how do you tell them from 114s? (if the 114 doesn't have the roof-mounted headlight)

115/117/118 - 117s and 118s seem completely identical as far as I can tell. 115s don't have corridor connections between carriages but is there a way to tell from the front?

127 - Aside from engine noise and higher seats?

120/126 - Any difference at all between these two?

Any help would be greatly appreciated!

 

[73001]

The 114s were about 6 feet longer than the 107/108... they have an extra big window between the passenger doors. 107/108 is a bit more difficult though.

 

[4SRKT]

114s were known as Derby Heavyweights on account of their extra length and higher capacity, as opposed to the Derby Lightweight 108s. The best way to tell 107s from roof headcode box 108s was that 107s were 3-car sets and had the prefix SC in front of their vehicle numbers 'cos they were all on the Scottish Region.

Pressed Steel 117s had a slightly more rounded body profile than 115s/118s, so were quite easy to tell apart. The best way to tell 115s from 118s (apart from the corridor connection) was again number of cars. 118s were 3-car and 115s 4-car. You were never likely to see them together though, as 115s only worked the Marylebone lines and 118s were Western Region sets off Laira.

120s and 126s looked nothing like each other IMHO.

 

[Welshman]

120s & 126s

120s
Built 1957
Blue Square coupling
3-car units
AEC engines but some had Leyland engines
Destination indicator boxes


126s
Built 1959
White Circle coupling
3-car units but had intermediate driving motors to enable 6-car formations
AEC engines
No destination indicator boxes
Some had buckeye couplers.

As far as I know, both classes were of similar width and length.
--- old post above --- --- new post below ---
107s & 108s

107s
built 1960
3-car sets
AEC engines
4-character headcode box above windscreen

108s
built 1958
2, 3 or 4-car sets
Leyland engines
slightly larger coach dimensions
2-character headcoach box below windscreen

 

[ChrisCooper]

Guards ends are another identification point. 127s for example had a small guards compartment without the extra window to the rear like very similar 117s had. Also, it's it's got a driving motor without the guards compartment it's not a 127 as 127s had 2 DMBSs. Then again, the same things apply to 115s too (which are basically the same, just different engines and transmission).

120 vs. 126 the guards end is important too. 120s were more like a Mk1 coach, with a seperate guards door and a double luggage door. 126s had a smaller luggage compartment with the guard sharing the same door. This also meant the passenger part was longer, 6 full size window bays instead of 5.

As 4SRKT says, where they were operating and formations are also a big idenfication points, but of cource this doesn't work in preservation as many are well outside their normal teratory and in different formations.

 

[Schnellzug]

117s and 118s were built by different builders, Pressed Steel and BRCW; one way of telling them apart latterly was that the 118s weren't refurbished and had the original panelling.

 

[bgstrowger]

A good way to tall the difference between a Class 107 and a Class 108 is the shape of the bodyside. The Class 108 is curved like a Mk1 coach, but the Class 107 is flatter.

A small difference between the Class 117 and Class 118 is the top of the headcode box. On the Class 117, it's flat whereas the Class 118 is curved.

 

[MK Tom]

Ah that headcode box difference is very useful! I can't see the difference between the 107 and 108 body shapes though?

 

[Schnellzug]

The class 107 was built of heavier gauge steel, if that's any help.

:-/

 

[Temple Meads]

I've never been very good at first gen DMU's, can someone tell me what this one is:

 

[Schnellzug]

That's the WSR's set, which I think is actually a Class 115 off of Marylebone. It has high backed seats, doesn't it.

 

[Temple Meads]

That's the WSR's set, which I think is actually a Class 115 off of Marylebone. It has high backed seats, doesn't it.

It's got 2 different seat designs, these are pretty turgid pictures but you get the idea, the one with the bloke reading is the middle coach IIRC, the second picture being the driving car seen in my previous picture.

 

[MK Tom]

Yeah that's a 115, but that's exactly my question, how can you tell it apart from a 117 from this angle?

 

[ChrisCooper]

Yeah that's a 115, but that's exactly my question, how can you tell it apart from a 117 from this angle?

From that angle, the two things to look out for are the number of doors, 9 on a 115 DMBS, 8 on a 117 DMBS, and you really need to know what you are looking for but I can see the smaller luggage compartment. If you can count 10 doors, it's not a 115 either because it's a DMS. Also it could be a 127 lacking one of it's two centre coaches, and from that photo you wouldn't tell.

Compare this http://upload.wikimedia.org/wikipedia/commons/9/99/1_CLASS_117_DMU.JPG
and this http://www.flickr.com/photos/dc-7c/6099202275/ (127 DMBS)

These are great shots showing the large luggage area on a 117 DMBS
http://commons.wikimedia.org/wiki/File:2_CLASS_117_DMU_DMBSO_Vehicle.JPG

and the smaller one on a 115 or 127
http://upload.wikimedia.org/wikipedia/commons/f/f4/Class_115_51859.jpg

 

[MK Tom]

Ah that's very apparent now! Thanks, very helpful!

What about classes 116 and 125? I completely forgot to include them!

 

[ChrisCooper]

Think 125s were to 116s what 127s were to 115s, in other words very hard to tell apart other than where they worked, but the 11x had Leyland engines and mechanical transmission wheras the 12x had Rolls Royce engines and hydralic transmission. Like many similar but different types they never worked together, the 116s operating around Birmingham and Cardiff, the 125s on the Lea Valley services (West Anglia).

To go back to the guards compartments, another big one was the 119
http://preserved.railcar.co.uk/Images/119/51073-2005-02-18-Ian-Francis.jpg
another rare example of a first generation DMU that had a seperate guards door and double luggage door.

 

[4SRKT]

I don't even remember class 125. Have you just made it up?!

 

[jonesy3001]

http://www.google.co.uk/url?sa=t&rc...ov21AQ&usg=AFQjCNFHZRGRfifzoUXBa3YNUajyYhedmA

 

[MK Tom]

Nope, they were very short lived, all scrapped in the mid-late '70s. Here's one:

http://www.flickr.com/photos/robertcwp/5813196882/

 

[dubscottie]

May I suggest a look at "First generation DMU's" by Kevin Robertson. Published by Ian Allan.

Got mine in Waterstones in Dublin so would imagine it would be widely available to buy (or look at) in the UK.

 

[4SRKT]

Ta. I can just about remember DMUs on the GN Suburban pre-electrification, but the only ones I can remember are Cravens class 105s.

 

[matchmaker]

120s & 126s

120s
Built 1957
Blue Square coupling
3-car units
AEC engines but some had Leyland engines
Destination indicator boxes


126s
Built 1959
White Circle coupling
3-car units but had intermediate driving motors to enable 6-car formations
AEC engines
No destination indicator boxes
Some had buckeye couplers.

As far as I know, both classes were of similar width and length.
--- old post above --- --- new post below ---
107s & 108s

Dates should be the other way round - the 126's were introduced in 1957, the 120's from 1958/9.

126's all buckeyed, 120's all screw coupled.

 

[ChrisCooper]

Doesn't help if you do a google image search for "class 125" you mostly get HSTs!

 

[jopsuk]

This site is good for 1st gen DMUs, though it is in the midst of a heavy rebuild

 

[A0wen]

Ta. I can just about remember DMUs on the GN Suburban pre-electrification, but the only ones I can remember are Cravens class 105s.

I believe the 125s went first as they were mainly used on the inner-suburban services (to WGC & Hertford Nth) - hydraulics had better acceleration than the mechanical transmissions - and the inner services went electric in 1975/6 whereas the outer suburban services to Royston went electric a year or two later.

 

[ChrisCooper]

I believe the 125s went first as they were mainly used on the inner-suburban services (to WGC & Hertford Nth) - hydraulics had better acceleration than the mechanical transmissions - and the inner services went electric in 1975/6 whereas the outer suburban services to Royston went electric a year or two later.

Yes, those old 312s FGE had didn't last long at all when you think about it, since they were originally on Roystons (original GE ones were slightly older and got displaced by the GEs to LTS because they had 6.25kV capability where the GE ones were 25kV only).

Didn't the 125s replace hauled stock (31s and suburban Mk1s) on on the GN suburban lines, after the Lea Valley was electrified?

Hydralics did have better acceleration, what with no pauses for gear changes and more powerful engines. I think they had reliablity issues though, hence why they were fairly early withdrawals and didn't get used to replace similar mechanical units on suburban lines when their lines (GN and Bed-Pan) were electrified. The bulk of those would last into the early 90s (115s from Marylebone, 117s from Paddington and 116s around Birmingham) and some 117s were still around at privatisation (with Central and Siverlink).

 

[A0wen]

Yes, those old 312s FGE had didn't last long at all when you think about it, since they were originally on Roystons (original GE ones were slightly older and got displaced by the GEs to LTS because they had 6.25kV capability where the GE ones were 25kV only).

Didn't the 125s replace hauled stock (31s and suburban Mk1s) on on the GN suburban lines, after the Lea Valley was electrified?

Hydralics did have better acceleration, what with no pauses for gear changes and more powerful engines. I think they had reliablity issues though, hence why they were fairly early withdrawals and didn't get used to replace similar mechanical units on suburban lines when their lines (GN and Bed-Pan) were electrified. The bulk of those would last into the early 90s (115s from Marylebone, 117s from Paddington and 116s around Birmingham) and some 117s were still around at privatisation (with Central and Siverlink).

The 312s were on the GN until about 1986 when new 317/2s together with 317/0s being cascaded a couple of years later. Part of this was because the electrification was extended (Royston - Cambridge and Hitchin - Peterboro).

The 125s were moved across from the Lea Valley lines when they were electrified (late 60s?) and may well have replaced loco hauled diagrams or allowed other DMUs to be cascaded which caused the locos to be replaced. It probably allowed the withdrawl of some of the less successful loco classes (15s, 23s, 21s).

There may have been reliability problems, but the bigger issue was probably compatibility with other DMU classes - certainly the midland had stopped mixing hydraulics and mechanicals after some issues.

 

[Welshman]

Dates should be the other way round - the 126's were introduced in 1957, the 120's from 1958/9.

126's all buckeyed, 120's all screw coupled.

May I refer you to Brian Haresnape's "Diesel Multiple Units - The First Generation" published by Ian Allan Ltd 1985 ISBN 0 7110 1495 7.

According to him, the 120's were introduced in 1957 and the 126's in 1959, and it was his dates I quoted.

The same book also has a picture on p.56 of a 126 leaving Kilwinning for Ayr, and I'm sure it has a screw coupling!

 

[4SRKT]

The same book also has a picture on p.56 of a 126 leaving Kilwinning for Ayr, and I'm sure it has a screw coupling!

The one thing about 126s I can remember with any clarity (apart from how appalling riding from Glasgow to Stranraer was in really run down examples at the end of thier lives) was the buckeye coupling, which was unusual on DMUs. Maybe the picture you saw had the front buckeye dropped and a screw hung on the drawbar hook?

 

[MK Tom]

and some 117s were still around at privatisation (with Central and Siverlink).

117s were still in use with ScotRail up to 1999 and Silverlink up to 2000. Pretty amazing when you come to think of it that first-gen DMUs were still in regular use that recently. Of course as we all know 101s carried on three years after that and got celebrated as the last and most long-lived first generation DMU class...

...Except we now have three class 121s on the main line that are 52 years old!