Confused about all the different coupler types available for N-Scale these days?  You're not alone.  Don't worry, in the next few minutes we will help you sort them all out so you can make informed decisions about what's best for you.  In a nutshell, there are two basic types of N-Scale couplers - Rapido and Knuckle.  For those that model the European railways, there's a different choice which we'll discuss later.  For now, you only have to concern yourself with Rapido couplers and Knuckle couplers.

The very first N-Scale models were designed to be nothing more than toys so it should be no surprise that they came to market with a very crude "hook and loop" coupler.  The originator of N-Scale, the ARNOLD-RAPIDO company quickly found out that these couplers just wouldn't suffice so they quickly developed a new coupler which they dubbed the Rapido coupler.  The Rapido coupler loosely resembles a square with one side cut out.  While it may not look anything like a coupler on a real train, it has remained in use virtually unchanged for the last three decades.  This speaks for itself in regards to it's reliability.  The Rapido coupler is still in use today although it's days are numbered as most manufacturers are now offering knuckle couplers as standard equipment.  Perhaps the best thing that ARNOLD-RAPIDO did was to allow any N-Scale manufacturer that wanted to use the Rapido coupler on their equipment to do so freely.  This was a very smart move on their part since it quickly standardized things and allowed equipment from different manufacturers to work together.  If not for this single gesture on the part of ARNOLD-RAPIDO, N-Scale may not have gotten as far as it has today.

The Rapido coupler.  It may not look anything like a coupler on a real train but it has been a reliable standard for over 30 years.

The Rise of the Knuckle Coupler

Although the Rapido coupler was working well, in 1972 the KADEE company, which is known today as MICRO-TRAINS, introduced their first boxcars with a new knuckle style coupler that not only looked more like the couplers on real trains, it also acted like them!  The KADEE coupler, as it was called back then, was able to uncouple magnetically and then re-engage without locking to allow the car it just uncoupled from to be pushed into a siding.  This is known as pre-coupling and for the first time it allowed prototype switching (or shunting as it's known it Europe) moves to be executed flawlessly without the operator having to use his or her hands at all!  As you might imagine the N-Scale modeling world was very enthusiastic over this new coupler however, KADEE decided not to offer their new system to other manufacturers.  The only place to get it was from KADEE and as a result it didn't catch on as fast as the Rapido coupler did.  Also, while the prices of the KADEE (MICRO-TRAINS) products were reasonable, many model railroaders stayed away from the new system because the costs and time involved to convert all of their existing equipment could be very high depending on how much they had already acquired.

The MICRO-TRAINS coupler.  The original and still the King of all of the knuckle couplers features magnetically operated uncoupling.

So how exactly does a magnetically controlled coupler work?  It's quite simple actually.  Each coupler has small metal rod is inserted into it.  This rod is commonly referred to as the "trip pin" since it's primary job is to "trip" the uncoupling mechanism into action.  The "trip pin" is curved upward and does a reasonable job of simulating the brake hoses on a real train.  Getting back to our model couplers, the train is coupled together normally and then taken to a special spot on the layout where a magnet has been installed between the rails.  The two pieces of rolling stock that are to be uncoupled are positioned over the magnet and then train is completely stopped.  This lets the slack out of the train and the forces of the magnet push the two metal "trip pins" apart which allows the uncoupling to take place.

In all fairness we should mention that most hobbyists don't actually use the uncoupling magnets.  In many cases they work a little too well and provide a lot of unwanted uncoupling or "breakaways" as they are known.  This can be prevented by using electro magnets however, it seems that most hobbyists are quite satisfied uncoupling by hand or using a small screwdriver.  The advantage here being you can uncouple anywhere on the layout and not just where the magnets are.  In spite of the preference for not taking advantage of the magnetic uncoupling ability of MICRO-TRAINS couplers, they became the undisputed King of the knuckle coupler because they worked well, were easily obtainable and offered a large variety of solutions to convert almost all manufacturers of locomotives and rolling stock to their system.

Others Come On Board

In the early to mid 1990's several N-Scale manufacturers, including KATO, PRECISION MASTERS (since acquired by RED CABOOSE) , INTERMOUNTAIN RAILWAY COMPANY and ROUNDHOUSE (Model Die Casting Co.) all offered versions of a knuckle style coupler.  Although all of these couplers could be coupled to the MICRO-TRAINS couplers and to each other with varying degrees of effort, none of them offered all of the advantages that MICRO-TRAINS did.  Hence, none of them ever became widely adopted enough to unseat MICRO-TRAINS as the standard coupler of choice among those modelers who preferred to use the knuckle style coupler.

The UNIMATE coupler was produced by PRECISION MASTERS and now owned by RED CABOOSE.  It never really gained wide acceptance.

In the year 2000 ATLAS introduced their Accumate coupler which was a knuckle coupler that could be operated magnetically.  In 2001 KATO also introduced a magnetically operated coupler of their own which has received positive reviews. The KATO knuckle coupler is unique in that it doesn't come with the "trip pins" installed thus allowing the modeler to make the decision whether or not they wish to use it's magnetic capabilities or not.  Unfortunately, it is only available on KATO locomotives and rolling stock, not separately.  We understand that will eventually change.

The KATO coupler.  A beautiful design that couplers very close and lets the modeler decide on whether it should work magnetically or not.

Let's get back to the ATLAS Accumate coupler for a moment.  In 2002, in a somewhat surprising move INTERMOUNTAIN RAILWAY COMPANY abandoned their own knuckle coupler and adopted the ATLAS Accumate as their standard of choice.  That lasted a couple of years but now all INTERMOUNTAIN RAILWAY COMPANY models use the MICRO-TRAINS coupler as their standard of choice.  Also surprisingly, RED CABOOSE who you may remember purchased the tooling and rights to the PRECISION MASTERS knuckle coupler (a.k.a. the Unimate coupler) now offers most their products with MICRO-TRAINS as standard equipment.  Although ATLAS is offering most of their locomotives and rolling stock with Accumates, Rapido couplers are still included with most models and can be installed by the purchaser if they choose.

The INTERMOUNTAIN coupler now seems to have been abandoned.  They used the Accumate coupler for a year or so as shown below.  Today however, all INTERMOUNTAIN cars now come with MICRO-TRAINS couplers as their standard of choice.

In 2008 a new competitor arrived on the scene.  The McHenry coupler now comes standard on ATHEARN models.  It is extremely reliable and couples nicely with other brands of knuckle couplers.  Some have criticized it for the small spring that resides on one side but it is hardly visible under normal viewing angles.  Close-up photos such as ours shown below emphasize the spring more than normal.  At initial introduction the McHenry coupler is only available on ready-to-run ATHEARN models but some reports indicate it will be available as a stand alone product at a later time.

The McHENRY coupler is the latest knuckle coupler in N-Scale.  It was introduced in 2008 and initially only available on ATHEARN models but promises to be available as a stand alone product later on.

So who will win the "coupler war"?  Well, YOU DO!!!  Today's N-Scale modeler has a lot of choices but the important point here is that the industry is now offering most equipment with knuckle style couplers and putting the Rapido coupler to rest.  The only exception to this are the European firms such as FLEISCHMANN, MINITRIX and ROCO who still offer the Rapido coupler as standard equipment with an option to upgrade to the FLEISCHMANN Profi-Coupler if desired.

The ATLAS Accumate coupler has gained wide acceptance and is now used as standard equipment on all ATLAS models.

A Coupler Just For European Trains

Remember back in the first paragraph when we said that European modelers have a different choice?  Well the FLEISCHMANN Profi-Coupler is it.  In German, the word "Profi" translates roughly to "Expert" and as such the FLEISCHMANN Profi-Coupler is designed with the more advanced modeler in mind.  It allows for pre-coupling just like the American knuckle style couplers do and it does couple the cars very closely however, this coupler is not a knuckle and it's not very prototypical looking.  In fact, it really does not resemble any specific European prototype coupler that we are aware of.  The FLEISCHMANN Profi-Coupler does not work magnetically, it only works with an electrically operated coupler track which can be tricky to install on layouts that do not already use the FLEISCHMANN Profi-track system.  Another disadvantage to this coupler is the price.  They are not cheap and you have to buy them in bulk quantities.  Also, adapting some older European locomotives and stock can be very difficult.  We do have customers that use this coupler system and are extremely happy with it however, as it's name suggests, it may not be the best choice for the average European modeler.

The FLEISCHMANN Profi-Coupler.  While expensive and difficult to retrofit on older stock, it will couple your cars literally buffer to buffer.


Before we conclude, here's one last trick.  If you are still not sure which coupler may be best for your needs you can try several of them out at once.  Simply make your own "conversion cars" by putting a Rapido coupler at one end and a knuckle at the other.  You can have some locomotives with Rapidos and some with knuckles and you can experiment with different systems until you decide which one works best for you.

We hope that we were able to demystify N-Scale couplers for you and have provided you with enough information to make an informed decision about which N-Scale coupler system may be right for you.  Of course, your choice ultimately depends on your own interests and the way you want to run your layout.  Each system has it's own advantages and disadvantages.  There is no right or wrong choice.  As long as you are having fun running your trains, that is all that matters.