You probably hear about them all the time when working with your model train, and you might even have a rough idea of what a model train coupler is.
It’s that little bit of metal that sticks out and joins the cars together! This article is a deep dive into what a train coupler is, how they work, the different types, and what you should know about them if you want your layout to be as authentic as possible.
What Are Train Couplers?
Train couplers are small but also one of the most crucial parts required for a functioning railway system. This tiny piece of metal is responsible for holding each train car ‘coupled’ or joined to the net one.
Since its emergence in the 19th century, this equipment has undergone various modifications over the years.
Starting off with the popular link-and-pin design, the train couplers evolved over the years, their quality of withstanding both tension (pulling) and compression (pushing) being improved upon. Gradually, more practical designs were developed, and most train cars today will use what’s called a knuckle coupler.
What are the Different Kinds of Train Couplings?
Buffers and Chain
The most common coupling derived from British roots, buffers, and chain couplers are still widespread in the UK and EU. A long, dual, or tri-chained link joins hooks on the connected cars.
The buffers help resist the impact loads, while the hooks and chains are used to keep the cars together.
Although early designs were fine for mineral wagons, it was a whole different story for passenger coaches, and improvements were made by switching the center link for a turnbuckle that keeps the vehicles together in a more stable fashion.
Karl Albert, the former director of Krefeld Tramway, came up with the Albert coupler in 1921 to manage safety issues. The design features a slot coupler with a pair of pins and a key.
The cars that had to be coupled were brought together, and both couplings were directed in the same way.
After a pin was inserted, the cars were pulled to further align the coupling, followed up by the insertion of the second pin.
This was quite a hit with narrow gauge lines and the tram systems.
Despite them becoming outdated in the 60s, the Albert couplers still get fitted into modern cars as an emergency measure for towing malfunctioning locomotives.
Link and Pin
The link-and-pin was popularized by usage on North American railways. The working principle is simple, and is a pretty standard trope in old westerns, but isn’t really used these days.
The system struggled for several reasons, the big ones being a lack of standardization in pin height and size of the links, as well as them being dangerous to fit together.
The coupler includes a tube-like body with a cylindrical link. The procedure was rather long, complicated, and often times, dangerous for the brakemen who fitted them.
Two kinds of radial couplers were used all through South Africa. The Johnston coupler, otherwise known as the bell link and pin coupler was introduced in 1873.
Like the name, it worked similar to the link and pin couplers, but they were bell-shaped.
Bell-and-hook coupler was the other which was introduced in 1902.
Multi-function couplers or fully automatic couplers can connect rail vehicles together without human assistance. They’re better than what’s known as an ‘autocoupler’ as the latter only managed the mechanical side, not the electrical or air-brake side in this day and age.
Most of the trains with these types of couplers installed in them are used in both passenger and transport locomotives that require mass transit or lots of cars to complete their operations as they’re quicker than doing it manually.
What Couplers do Model Trains use?
Model trains mainly feature three kinds of couplers:
Horn Hook Couplers
The couplers you got with your original products? Horn hook couplers. They don’t resemble prototype couplers at well. They depend on side pressure to keep everything together. That causes an issue when backing up, as the excessive reliance on pressure causes derailment.
The Rapido couplers look somewhat like squares with a side cut out. It doesn’t look like something you’d find in a real train, but it has been used for the past thirty years anyway. The purpose of the first N-scale models was to be considered simply as toys, so they came in an unimpressive “hook and loop” form. The makers were quick to realize that it wouldn’t remain for long, so they came up with the Rapido couplers. The couplers were standardized and became huge in the market.
These look better and have a more prototypical feel. Knuckle couplers complement magnetic uncouplers well. When the trains are backing up, there isn’t much derailment. Manufacturers like Kadee, Atlas, Athearn, and Kato make these.
What is the Best Train Coupler?
The originators of the knuckle couplers are still some of the best in the industry. Kadee features a wide range of couplers, some special versions for transforming older locomotives as well as care, shelf, and scale knuckles.
All of Kadee’s products are constructed of top-notch parts and are ones we use ourselves! The KADEE 206 Insulated Coupler has become a fan-favorite recently.
It’s easy to use, of superior quality, and while it’s not a knuckle coupler, we just appreciate the old school pin aesthetic.
Best Brand of HO Scale Couplers
Kadee knuckle couplers have been one of the best brands of model train couplers since they started operations.
They provide the biggest range of couplers and come with a bunch of special versions for different scales as well as for converting older cars and locomotives.
Generations after generations, the No. 5 knuckle coupler has been the standardized coupler of Kadee.
On the HO scale, this particular model has been popularized for providing the best versatile service. It is also extremely user-friendly and an easy-to-use conversion chart can be found on Kadee’s website.
Kadee is an awesome brand that makes all of its couplers out of metal, and you should consider upgrading your couplers to them if you want a cleaner finish on your existing model trains.
Best Brand of O Scale Couplers
Once again, we’re looking at Kadee couplers as the winners of best O scale couplers. The finish on their O scale come out ahead of the competition for three reasons:
- They work better
- They look better
- They stay coupled for longer periods of time
Presently, these couplers commonly come in a 2-rail scale, but Kadee does provide some accessories for 3-rail builds too.
But if you want to enjoy an authentic feel from your model trains you might want to avoid the 3-rail track which doesn’t have the most realistic appearance at O scale anyway.
Best brand of N scale couplers
Originally most N-scale couplers were 2 types – Rapido and Knuckle. Over time, the use and demand of Rapido couplers diminished with Knuckle couplers capturing the market share.
The standardized knuckle couplers were first introduced by Micro-Trains the helped perfected by the Kadee company.
The ability of Kadee N-scale scale couplers to uncouple magnetically and re-engage without locking immediately is an awesome thing to see as your model train rolls through the yard.
The MTL (Micro-Trains Line) makes 2 types of N-scale couplers – Magne-Matic knuckle and True-Scale couplers.
True-Scale couplers were developed based on providing a more true-to-life scale of couplers for model train cars as well as adding more prototypical features.
While we think that Kadee does an amazing job on couplers as a whole, we’re going to award MTL the best brand of N scale couplers!
Are All N Scale Couplers Compatible?
So, thanks to standardization, all N scale couplers are meant to be compatible with each other.
The only slight problem is not all couplers are made to the same quality standard.
You’re going to find that some N scale couplers like Bachmann are ever so slightly larger in size and will sometimes uncouple with other brands.
The easiest way to fix this is to do is to change out the couplers yourself and standardize your layout instead.
Problems With N-Scale Couplers
One of the biggest problems you’re going to face with N scale couplers is just the sheer volume of them out there. Do you choose Kato, Bachmann, MTL? Plastic or Metal? And even then, each brand has a ton of different coupler variations to choose from. It can be a bit overwhelming at times!
After deciding upon the brand, the next problem is the conversion. While most manufacturers now design their products with knuckle couplers, some still manufacture using the Rapido couplers.
Using Z Scale Couplers in N Scale
Installing Z-scale couplers in N-scale couplers gives a more in-scale appearance. MTL couplers facilitate an easy installation process, but there are other ways as well.
Start by separating the main body from the frame. Flip it upside down to remove the trucks and stirrup steps.
Adjust the height of the couplers by adding styrene spacers to the pads. Next, cut the spacers to your desired length and attach them over the pad with an adhesive.
After the glue sets, drill through the mounting hole and the spacer cut the screw threads and remove any excess material with a knife. Try to maintain the glue tension.
For final touches, paint the spacers only after assembly. Before you end it, add some dry lubricants on the front and sides of the couplers.
And voila, you’re done!
So that’s it for train couplers! If you’d like to look more into model trains, you can have a look at our guide to the best brands of model trains, or even take a look at a model train for christmas coming up!
Peter has been building model trains for longer than he can remember. An avid fan of HO and O scale this blog is a creative outlet to allow him to dive further into other scales and aspects of the model train community and hobby.