Large Scale Couplers

Latest update: 4 November 2016

Prototype Coupler Types

Many coupler types exist in the prototype, but only a few of them are relevant for our large scale trains. Wikipedia does a good job on explaining how they work, so I’ll leave you with some relevant links.

Large Scale Couplers

Hook and Loop Couplers

Most manufacturers provide “hook and loop couplers” by default. The hook and loop coupler is the only standard coupler for large scale trains. The coupler consists of a wide loop, and a sprung hook for easy coupling and uncoupling.

Some manufacturers install a hook on only side of the car (“asymmetrical”), others install a hook on both ends of the car by default (“symmetrical”). Symmetrical couplers are more reliable, as an accidental uncoupling on uneven track is unlikely.

Hook and loop couplers Hook and loop couplers

Hook and loop couplers are not prototypical, and are considered big and ugly. Since they are almost always provided as standard, not many people see a reason to change them.

A narrower version of the standard hook and loop coupler was introduced by a small German company a few years ago. The so-called “S-KuPLiX” coupler is much smaller and therefore visually less distracting, while remaining compatible with the standard hook and loop couplers. I reviewed them here: Review: S-KuPLiX Coupler.

Knuckle Couplers

Most manufacturers of American style trains include a set of knuckle couplers in the box, so customers can decide if they want to run the standard hook and loop couplers, or the more prototypical knuckle couplers.

Each manufacturer supplies its own design of knuckle couplers, so compatibility between brands is not guaranteed.

Most knuckle couplers can either be truck mounted or body mounted. Truck mounted knuckles can be a direct replacement for the hook and loop couplers, as they are mounted in the same place. A small modification to the coupler arm may be needed. Body mounted couplers often require major modifications, because the coupler boxes all need to be mounted at the same height to function properly. Body mounting is more prototypical and the preferred way of installing knuckle couplers, but sometimes truck mounting is a better option if your layout features small radius curves.

The video below from “Garden Trains” on YouTube gives a good insight into knuckle couplers and truck/body mounting. While the video discusses USA Trains couplers specifically, the things mentioned in the video apply to other brands as well.


LGB offers truck mount knuckle couplers under article number 64193, and are designed as a direct swap for the default hook and loop couplers. The LGB couplers have a locking pin as per the prototype.

LGB 64193 Knuckle Couplers


Aristo made several versions of their knuckle couplers. I don’t know much else about them…

Aristo-Craft Knuckle Coupler

USA Trains

USA Trains products come with a set of truck mount knuckle couplers (Art.No. R2010). USA Trains also offers a body mount coupler box (Art.No. R2012) to use with these knuckle couplers. The couplers have a locking pin as per the prototype.

USA Trains Truck Mount Knuckle Coupler


To avoid incompatibility when mixing brands, a lot of people prefer to fit a single brand of couplers to all their rolling stock. And that’s where Kadee couplers come into play. Kadee is massively popular in H0, and is also the most popular brand for large scale.

Kadee offers two styles of couplers: the old “original style” couplers and the new generation AAR Type “E” couplers. The type E couplers are more realistic, and are backwards compatible to the orginal style couplers.

Kadee offers both styles for both G scale and 1 scale. Kadee’s 1 scale couplers are 1:32 scale, their G scale couplers are 1:24 scale. The G scale couplers are used for 1:20,3 to 1:24 scale. 1:29 scale is a bit in between, so both coupler sizes can be used there.

Kadee couplers do not feature a locking pin, but instead have a curved rod hanging below the coupler. Although not prototypical, the rod is made to look something like a brake hose so it still looks pretty good (if you ask me).

Kadee offers a large variety of both body mounted (left picture) and truck mounted couplers (right picture).

Kadee 906 Body Mount Coupler Kadee 908 Truck Mount Offset Coupler

Link-and-pin Couplers

LGB 64777 (Link)

LGB 64777 Link-and-pin Couplers

Buffer and Chain Couplers

Pretty much nonexistent in large scale. Most people keep using the hook and loop couplers on European style rolling stock.

Overview of Couplers Installed by Manufacturers

  • Aristo-Craft: ?
  • Bachmann: ?
  • LGB: hook and loop installed (single hook, one extra hook supplied)
  • Liliput: hook and loop installed (double hook), knuckles supplied
  • PIKO G: hook and loop installed (double hook)
  • Train Line: hook and loop installed (single hook, ?)
  • USA Trains: hook and loop installed (double hook), USA Trains truck mount knuckle couplers supplied

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