Outside Axle Guards (or W Irons)

Any aspect related to the prototype stock.
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lindsay_g
Posts: 404
Joined: Mon Aug 13, 2012 8:43 pm

Outside Axle Guards (or W Irons)

Post by lindsay_g »

Amongst the items included on the recent TLM etch were 3 types of W irons (apologies if the purists want to call them axle guards) which I'm going to term straight, cranked or mixed (hopefully for simplicity) as follows :
Excuse the deliberate mistake - straight legs are CR08!!
Excuse the deliberate mistake - straight legs are CR08!!
Axle Guards.jpg (58.77 KiB) Viewed 3406 times
Having purchased a few of these, amongst other items, I set about identifying initial wagons to model. The first contender for the straight W irons that sprung to mind was a 10t brake van which I started to draw for production on a Silhouette Cutter. However, I quickly remembered that there 2 distinct variants of the straight W iron, one having a more acute angle to the outer legs than the other - and obviously the one supplied on the etch was the wrong one for the brake van. Between that and ongoing correspondence between myself and Steve Parsons, I've been delving into usage of the various types coming up with the following :

Outside W irons seemed to be prevalent in the 1860-70's and a number of variants on the straight leg version probably indicates evolvement, or dictats from head engineers, or local preference. The vertical posts on outside framed mineral wagons (bogies) restricted ease of application which could be the reason for the mixed format evolving. As time went on it probably became clearer that it was easier to adopt cranked W irons on all bogies. Drummond arrived and outside irons went quickly out of favour. Now, that's not meant to be a definitive history but a synopsis of what might have been the case.

So, let's start looking at each style :

Straight
Within this, there were a good few variations. The most noticeable is the angle of the outside legs with most being to a wide angle (possibly not all the same angle) and a few to a much acuter angle. Some of the outer legs were rounded at the top, others were angled. Some had the outer legs and the semi circle of the inner legs all the same height, others had the outer legs extending higher than the semi-circle.

Wide angled legs were seen on the greatest variety of vehicles including pig iron wagons, rail wagons, swivel wagons, covered vans, early 1870 cattle wagons (but those ordered c1874/5 had narrow angled legs), open wagons, open carriage trucks, flat wagons, and gunpowder wagons....plus the odd pug tender.

Narrow angled legs were fitted to 10t brake vans and some swivel wagons.

Mixed
Usage of these would seem to have been limited mainly to pre-7t bogies. So far, a ballast wagon is the only other wagon that I've come across with them fitted. And just to introduce a possible one-off before moving on to cranked legs, an early 6t(?) bogie (p82 of the wagon book) had one mixed and one straight W iron on the side photographed.

Cranked
The cranked legs were probably the most prolific but used possibly on fewer types of vehicles. They seem to have been introduced with the move to 7t
bogies and all such vehicles I've seen so far are fitted with them. Perhaps they offered more freedom of fitting between the upright pillars of the outside frame of which there were a good number of subtle variants. The 10t loco coal wagons ordered in the 1870's were also fitted with these cranked items. Beyond that, they only seemed to be fitted to vehicles in limited numbers including pre-diagram swivel wagons (p19), open wagons (60), and stone wagons, plus the odd pug tender.

Is that a fair assessment? Can anyone provide more info on what format was used on which wagons and why? Are there exceptions such as bogies built to 7t capacity having other than cranked irons?

Lindsay
Dave John
Posts: 205
Joined: Wed Aug 15, 2012 7:42 am

Re: Outside Axle Guards (or W Irons)

Post by Dave John »

Seems a fair assessment lindsay. I made up some of the old MWC kits years back, I came to the conclusion looking at the pictures available that they built the bodies with the outside framing where it needed to be then adjusted the W iron to fit the bits in between.
Graham Tipple
Posts: 102
Joined: Tue Dec 27, 2016 8:16 pm

Re: Outside Axle Guards (or W Irons)

Post by Graham Tipple »

Hi folks. Thanks for this thread and all the knowledge that is behind it. Could I ask how we do the axleboxes and springs when using them? Best wishes, Graham
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