Home-designed
elongating drawbar (1)

Original page created on 24/04/2021; updated on 07/03/2022.

Commercial elongating drawbars

I have adapted elongation drawbars on many older models, Jouef, Hornby, Fleischmann, MMM-RG. Here are some examples.

Sometimes Roco 40343 or 40344 are suitable, but this is quite rare as they are very thick. Their elongation is satisfactory. Here is a USI MMM-RG coach equipped with these drawbars.

Most of the time, I used nickel silver Makette KKK. Among these, there is the large KKK-1 model, more adapted to bogie vehicles, and the small KKK-2, which I did not use very much because its elongation is rather short.

Here is a KKK-2 mounted under Kangourou Jouef. The NEM box has been mounted upside down, i.e. facing upwards, to obtain the desired height.

Here is a KKK-1 mounted under Gas Jouef, on which I decreased the distance of the pivots (from 138.5 to 132.5), which is too much compared to the reality (135.1). I had to do it to “fit” the drawbars.

The problem is that Makette’s are no longer available. AMF87 still offers some, of Huet origin, but they are “compact” models with a short elongation. However, Huet used to offer larger drawbars.

Anyway, even with the Makette KKK-1, I have been confronted with elongation deficiencies, and installation difficulties, for example on the Gas Jouef covered wagon above.

Other drawbacks of the Makette KKK-1: it is not (or very little) adjustable; its mobile arm is fragile, and it is impossible to reinforce it (the Huet is better on this point).

Hence, my idea to try to make a drawbar with a similar design, but with fewer disadvantages: greater elongation, possible adjustment and… availability.

Specifications

This home-designed drawbar should:

• allow sufficient elongation for any curve down to 350 mm;
• be able to fit on a vehicle with a small overhang;
• be able to be fixed by its front or rear;
• have rear fixing lugs sectionnable to reduce space requirements;
• have a NEM box adjustable in length and height.

Prototype

So, this drawbar is very much inspired by Makette’s and Huet’s, but with a larger “elongation base” — I mean the distance between the two pivot points: 18 mm instead of 12 for the Makette KKK-1 and 14 (at the most, I don’t know the exact value) for the older Huet, allowing a greater elongation.

Here is a study for its implementation on a Gas Jouef wagon.

The coupling system is not shown, but the distance between the drawbars remains 15 mm, regardless of the curve radius, in accordance with NEM 362 (dimension e = 7.5). The buffers, which are extended, do not touch each other in the curve.

Some prototypes were etched with other parts, taking advantage of an order, and mounted on a Jouef Dd4s luggage van being renovated.

Click the picture to get a closer view of the drawbar.

On this prototype, there is still a spring hooking tongue at the rear, which increases considerably the space requirement (even though the spring is not tensioned). Furthermore, it is not adjustable in height, but only in length.

Note the fastening with self-tapping P-tite screws, which are very small. A thin double-sided adhesive fastening does not last long. Gluing with CA is possible but problematic if you want to be able to dismantle.

The luggage van has been driven in this way at the head of a train of about ten coaches without any problem.