There are some things I just won’t compromise on.  One of those things is diaphragms on my passenger and express cars.  I want them.  Of course, they make coupling and uncoupling more difficult.


I did do some limited testing with Sergent couplers made for Walthers heavyweights, but was relatively unsuccessful.  I had trouble with aligning them and getting the Sergent passenger car uncoupling tool in below the diaphragm above the coupler.  I haven’t given up although I have come to a compromise as I had operations looming at the time.  Here is my temporary solution….

For passenger & express cars I use Kadee #158 “scale” couplers.  I do not like having track magnets either above or below the track, nor electrically activated uncoupling magnets.  I’d rather uncouple with a Kadee tool or skewer.  But, obviously, the diaphragms get in the way.  Another problem to overcome is the spring-action that keeps the diaphragms together – they work against the need to have slack between the knuckles in order to uncouple.

The coupling of cars with the scale Kadee’s is as expected.  The spring feature on the Walthers cars is overcome easily when a car is backed onto another one.  Sometimes a nudge by hand from the opposite end is needed, but usually they work well on tangent (straight) tracks.  Like most other Kadee’s they won’t work on curved track although if the engineer moves slowly enough, the conductor can hold the coupler to one side to effect coupling.  Coupling isn’t the problem.  Uncoupling is.

I made an uncoupling tool to be used with a specific procedure.  This tool is shown in the picture below.  I bent a length of 3/64″ diameter brass wire and taped it to a miniature flash light.


Here is a close-up, the tape being electrical tape in two places.


The hook on the wire is intended to grab the Kadee trip pin attached to the coupler.

Here is the procedure:

  1. Wipe away moisture from thumb and index finger on the hand that will touch the cars.
  2. Turn on the light (this really helps in finding a trip pin).


3. Place thumb and index finger of one hand as shown below.  Squeeze the cars straight back to provide slack between the couplers.


4. Insert the hooked end of the tool from the end of the trip pin.


5. Pull trip pin outward; uncoupling 99% of the time is very easy.  If not successful, repeat above steps.  When cars are uncoupled, with tool in place, move cars apart slightly.


6. While still holding the cars in place, remove the tool by moving the hook portion along the length of the trip pin.  If the cars are not held in place, there is a chance that they may be derailed if the tool is not cleared from the trip pin when it is moved away.


7. Turn off the light.

The picture below shows the slight kink I apply to the end of the trip pin to make grabbing it easier.


Design is often about compromise.  I am happy with this interim solution until I find a way to make Sergent couplers easier to work with.