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Modern Image Coupling – For DMU / EMU Trains

On modern image trains today many are equipped with Scharfenberg type couplings. This style of coupling is usually found on the likes of DMU / EMU trains like the class 180 Grand Central  seen in the photo below.

The Scharfenberg coupler face has a protruding cone with a matching cup. The cone contains inside a rigid metal hoop which is connected to a revolving, spring-loaded metal disk with a notch on the opposite side. When ready to couple, the spring turns the disk so the hoop is extended from the cone.When the cars meet the hoop enters the cup on the other coupler, stopping against the disk. The hoops are then pressed back into their own coupler, causing the disks to rotate until the notches align with the hoops. After the hoops have entered the notches the disks spring back into the hoop extended position, locking the coupling. In the coupled position forces on the hoops and disk will balance out, which means that the Scharfenberg is not dependent on heavy latches to stay locked as many other couplers are.

This video shows how the couplers work:

Working Model Couplings

So a internet search to find similar Scharfenberg couplings found a couple worth looking at. One being by Hornby for their Hornby International range & another by a company call Tomix. The Tomix one looks ideal for retro fitting into the likes of the Bachmann Class 220 & 221 Voyagers / Super Voyagers. The Tomix one we’ll take a look at in a future article.

The Hornby International Scharfenberg couplings come as a pack of four (two pairs) working couplings. The part number for these is HC8040 & cost around £10 per pack. They are suitable of any DMU / EMU model that has a NEM coupling box, using these will also bring closer coupling of the models too! On some British outline models you may need to change the NEM coupling box for a longer one.

For this article i’ve tried these couplings out on two Bachmann class 150 DMU models. On my layout the mainline tightest curves are 24″ radius whilst on the lower level storage yard area there is some standard second radius curves (438mm). In testing they seem to just about cope with second radius curves.

Below on the left is the Tomix HO scale coupling (also available N Gauge) & on the right Hornby Internationals coupling.

Fitting The Couplings

First start by placing your DMU / EMU upside down in a loco service cradle. I’m using a Peco service cradle here.

  • Firmly hold the NEM coupling box as shown with the two opposing arrows.
  • Hold the tension lock coupling & pull the coupling out of the NEM coupling box. Some come out easier than others.




The coupling should pull out of the NEM coupling box. Place the coupling in your spares or model box for safe keeping.




The HC8040 coupling pack contains two pairs & comes in a blister pack as shown on the right. In the lower photo on the right, the two couplings at the rear have a flat smooth top side. This is the top or right way up & is how they should be when fitted.

The two couplings in the foreground are upside down & have a raised shaped section. These must face downwards when fitted.




The coupling must face the same way as shown on the right.




Now place the two prongs of the coupling into the NEM coupling box.

Push the coupling fully into the NEM coupling box.

Now repeat the procedure with the removal & fitting of the replacement couplings.




In the image on the right showing the coupling fitted.




So as per the real thing these couplings automatically lock when engaged. In the image on the right the two couplings are about to lock together.



Push or drive the unit till you hear the coupling click. The couplings are now fully engaged & locked together. Not the closer clearance with these couplings.



To uncouple you’ll see the shaped bar hanging down below the coupling. Use a flat bar, piece of card etc to lift both bars up at the same time. The two units can then separate & uncouple.



With the units coupled together on a straight this the gap between the two units around 2mm between the two gangways.



With the units coupled together on a curve in this case a 24″ radius curve this how much they open out to ride round the curve. In testing they seem to cope with curves as tight as second radius. In other testing they coped very well with no issues with them entering or leaving the incline on the layout.

So overall a nice quick & easy coupling upgrade for any modern image model that uses these types of couplings.

Would you be interested in using these couplings let us know below in the comments box.


Happy modelling.



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