Wagon frames, wooden or steel

[Peter King]

I am about to scratch build various LNWR goods vans c1920, whilst the LNWR Society offer superb info for us modellers, there seems no clear info on the type of under frame used wether wood or steel, is there a simple way of recognising which to use for each design. Peter.

[Caley Jim]

Steel underframes were usually made from steel channel, so you can see the lip along the lower edge and also the thin cross section of the headstock.  Also they don't have the washer plates above the W-hangers.  Having said that, some wooden solebars were 'flitched' in that they had a metal plate running all, or most, of the outer surface so you don't see washer plates on them, however, you would see the thicker section of the ends of the headstocks.

 

Jim

[corneliuslundie]

I only have volume 1 of the LNWR wagons series, but it gives details of construction for the period to 1903, during which period timber is stated to have been standard for underframes.

I was going to say that one give-away is the presence of iron washer plates as they are only needed on timber, except that the LNWR does not seem to have used them, preferring square washers, and sometimes the LNWR seems to have used flitch plates with timber underframes anyway.

There seem to be few drawings or photos in the book illustrating channel steel, though one is the drawing of a Diagram 9 open wagon, dated 1904. However the Diagram 103 opens introduced in 1910 had wooden underframes. and the cattle wagons dating from 1910 also seem to have timber.

So my approach would be to stick to timber unless proved otherwise.

Jonathan (not an LNWR expert)

[Regularity]

Generally speaking, on a wooden solebar wagon, the side cill (which appears as a plank on the side, but is actually there to hold the floor planks in place) is deeper, and notched for the lower 2” or so to fit between the headstocks, which will be of wood about 12”x5” in section. On a metal underframe wagon, the solebars and headstocks are usually from the same size C section metal, usually 9” or 10” by 3”, and the cill is the same depth as the floor thickness and is not notched.

 

That’s generally speaking, of course.

 

Get hold of Chris Croft’s articles in MRJ 12-15 and all will be explained.

[Compound2632]

From the Earlstown GAs reproduced in C. Northedge (ed.) LNWR Wagons Vol. 2 (Wild Swan, 2011), it's clear that all the standard designs of covered goods van, including D88, the last of which were built in 1923, had wooden underframes. Specialised types such as meat vans followed suit. In this respect, LNWR design was lagging behind that of the Midland, which had been building vans with steel underframes since 1911. These provided the starting-point for the LMS standard designs.

[Poggy1165]

It seems strange to me that (most) railway companies were quite slow to adopt steel frames. Yes, there always exceptions to the rule, but most persisted with wood.

 

One factor may have been that repair shops were simply better equipped to repair wooden wagons. Or maybe it was just the innate conservatism that (generally) pervaded railway culture.

[Compound2632]

Timber had to be bought in several years in advance.

[Regularity]

2 hours ago, Compound2632 said:

Timber had to be bought in several years in advance.

Because it doesn’t grow on trees.

 

It grows in them, which takes time. Then the trees need felling, the wood cutting. Then seasoning. Then treating. 
Not a quick job.

[Compound2632]

8 minutes ago, Regularity said:

Because it doesn’t grow on trees.

 

It grows in them, which takes time. Then the trees need felling, the wood cutting. Then seasoning. Then treating. 
Not a quick job.

 

I was cut short by the call to dinner. My point was that changes in design of wood-framed wagons required some advance planning and a sudden switch to iron or steel underframes might leave the company with seasoning timber on its hands for which it had no other use. An example of this can be seen on the Midland, where the cessation of the the programme of building thousands of D299 five-plank open wagons every year throughout the 1880s and 90s was followed by the building of nearly 3,000 D357 covered goods wagons - a design that had not been built for a decade, longer D362 wagons having been built since 1893. This is recorded as being to use up material on hand - the D357 covered goods wagon and D299 open had most underframe components in common.

 

As to the continued use of wood-framed wagons, for coal traffic they were preferable to steel as the latter corrodes more rapidly on contact with coal.

[PenrithBeacon]

It hasn't got anything to do with contact with coal. The coal was very wet from washeries and the wagons were quite often used for storage anyway. Basically the wagons were sodden. Seasoned wood copes better than mild steel in those conditions.

The SR used a proprietary steel for wagon underframes (can't remember the name) which had a very small amount (around 1%) of copper and the LMS later confirmed independently that this was the way to solve the corrosion issue, but wood was used as well as steel right up to nationalisation.

Regards

[Regularity]

2 hours ago, Compound2632 said:

My point was that changes in design of wood-framed wagons required some advance planning and a sudden switch to iron or steel underframes might leave the company with seasoning timber on its hands for which it had no other use.

I was agreeing with you.

[Poggy1165]

Extremely informative and interesting. Thank you. There is usually a logic to these things, but often it is not obvious. 

 

I suppose another factor in later years might have been the increasing difficulty in obtaining quality wood at an affordable price. One reason why some railways made great use of concrete and or steel for signal posts. 

Edited May 30, 2020 by Poggy1165

[Caley Jim]

On 30/05/2020 at 15:28, Poggy1165 said:

I suppose another factor in later years might have been the increasing difficulty in obtaining quality wood at an affordable price. One reason why some railways made great use of concrete and or steel for signal posts. 

Steel underframes, and indeed steel wagons, were lighter than wooden ones and so reduced the tare weight of the wagon (and the train).  For example, a CR Dia. 59 16T mineral wagon on a wooden underframe had a tare of 7t 6cwt, whereas one on a steel underframe tared at 6t 17cwt.

 

Jim

Edited August 12, 2020 by Caley Jim
edited to remove a stray letter

[Compound2632]

On 30/05/2020 at 15:28, Poggy1165 said:

I suppose another factor in later years might have been the increasing difficulty in obtaining quality wood at an affordable price. One reason why some railways made great use of concrete and or steel for signal posts. 

 

It's noticeable that as time went by, the width of the pine boards used for wagon sheeting went down - pre-1887, 3'8"-deep mineral wagons with four 11" planks were commonplace; by the 1890s such wagons were being built with six planks - approx 4 x 6⅞" + 7½" + 9" - and 4'0" deep wagons with seven planks, 6⅞". The Great Western went over from 1'10" deep opens with two 11" planks to ones with three 7¼" - 7⅜" planks c. 1879.