Preferred uncoupling device

Uncoupling of rolling stock is a topic that has consumed a lot of printers ink over the years. Many of us have tried under-the-rails permanent magnets and electromagnets in combination with knuckle couplers equipped with steel trip pins such as the well designed and built Kadee coupler. However, many have gravitated to using a wooden kitchen skewer operated by the 1:1 scale "hand of God" that looms into the 1:160, 1:87, 1:48 or whatever miniature world that we have spent hundreds of hours creating.

I have long subscribed to the premise that I avoid wherever possible "piercing the veil" of my miniature world that I have taken so much effort to create by routinely imposing my 1:1 "hand of God". I have tried the above-mentioned magnet approaches with decidedly mixed results. The under-the-rails permanent magnets work very well but are prone to unwanted uncoupling which quickly becomes very tiresome.

The under-the-rails electromagnets work very well but can only be powered for short bursts before they become over heated and are prone to burning out of even potentially becoming a fire hazard.

At long last Rapido Trains has designed the solution for me in their RailCrew On-Off Remote Uncoupler. 

This clever device can be easily mounted in the trackbed or even retrofitted from under existing rails using a standard hole saw. Of course retrofitting requires some deft handling of the hole saw when it breaks through the subroadbed. It must be mounted with the black line shown running lengthwise between the rails. Inside the grey plastic circular case is an arm upon which is mounted strong permanent magnets on each end. When the uncoupler is in the "off" position it won't uncouple cars because the permanent magnets are aligned underneath the black lines. When 12 volt DC power is applied momentarily (a momentary-on toggle switch is best for this) an electromagnet inside the device causes the arm to swing so the two permanent magnets are perpendicular to the black line. In this position the magnets have the effect of pushing the ferrous metal trip pin on the uncoupler (which are offset from the centre line) to move to the centre, thus uncoupling the cars. The advantage of this is that the uncoupler remains in this position until it is moved back again. However, I have noticed that if I forget to turn the uncoupler off, when the train starts to move the various bits and pieces of ferrous metal including other trip pins will cause the uncoupler to quickly reset on its own, which is handy.

An interesting feature of this device is the bright blue LED mounted in the top of the device at the mid-point of the black line. When the device is turned on (i.e., to uncouple) the blue LED shines up from the rails and illuminates the underside of the couplers, making it easy to see when they are positioned in the correct place. A slight backward movement of the cars will then cause them to uncouple. I also mount the optional blue LED in my control panels so they also light up when an uncoupler is turned on.

Here the uncoupler is in the "on" position and shows the uncoupler before ballast has been added to this piece of track.

The toggle switches operate my uncouplers. The one on the right is lit blue (the picture doesn't do justice to the blue colour - they are blue, believe me)

I strongly recommend the Rapido RailCrew On-Off Remote Uncoupler.