Rail joints in the garden

DCCWiki, a community DCC encyclopedia.
Jump to: navigation, search

Maintaining rail joins in the garden can be a bit more complicated than indoors. Indoor layouts are protected from dirt, industrial pollutants, rain, large temperature swings, etc. One of the biggest problems with outdoor railways is the constant expansion and contraction. Not only do we have to worry about the seasons, but every day, the track is moving.

The weakest link in garden railroads is the joints between sections of track. Rail joiners play an important role in maintaining structural integrity and electrical continuity. Some methods are better than others and are outlined below.

People typically use a high quality grease with the joiners or clamps to prevent corrosion or oxidization that causes loss of conductivity. There is a large controversy over 'conductive grease', some people may refer to this as conductive grease as it only helps to prevent corrosion at the joint. There is no such thing as conductive grease that can replace wires.


  • Rail Joiners - Typically slide over the lower part of the rail. Some vendors like Aristo use micro screws directly touching the rail surface to help ensure electrical connectivity and track integrity. However, they usually only have a screw on one side of the joiner and not both.
  • Rail Clamps - Rail clamps are typically larger and sturdier than rail joiners and are attached to the bottom portion of the track like a clamp. The screws are embedded in the structure or the clamp and do not come into contact with the rail.
  • Expansion Sections

Rail Joiners

Rail joiners have a two-fold purpose; to keep the track aligned, and to pass electrical current to the adjoining sections. Both LGB and Aristo have their own type of rail joiner, and their track can be used interchangeably. LGB has a friction fit, and Aristo has a joiner that uses screws to lock the track sections together, to guarantee a good electrical connection. The screws are small and can be found embedded in wax on the underside of the track sections. Each Aristo box of track comes with a special hex head screw driver to secure these screws. Good eyesight, or a pair of reading glasses is needed to work with these screws. A bag of these screws can be purchased from your dealer, since once you drop them, they are lost, unless you have a strong magnet to retrieve them from your ballast.

Screws and conductive grease will not prevent a track joint from eventually losing its electrical conductivity in the outdoor environment. Soldering joints using jumper wires is one solution to your electrical problems. The downside is that you have to drill the web in your track at each joint, clean off the oxidation, and use at least a 300 Watt soldering iron (or an expensive resistance system) to secure the jumper. With the iron you have to be careful that you do not melt your tie strip from the extreme heat. You will not be able to solder stainless steel track, and you are better off using a rail clamp.

Rail Clamps

Rail clamps have been know to relieve headaches as they promote greater electrical conductivity, and prevent derailments since they assist in better track alignment. Many modelers have had a great deal of success with rail clamps, and they are becoming more an more popular. Factors include heavy Florida monsoon rains in the summer and high humidity. The price clamps range between $2.00 - $4.00, depending on the style; this can add up quickly on a large outdoor layout. While this may seem high, if you have a section of your railroad that causes you constant electrical problems, rail clamps will can fix many of these issues.

Split Jaw

Split Jaw offer their clamps for either brass, aluminum, or stainless steel. Split Jaw has a three part fastener with two set screws, that is made to go over bare rail ends. It comes in sizes to accommodate all brands and codes of large scale track. Slit Jaw clamps come in various models and can either fit over rail joiners or bare rail. Split Jaw also offers insulated rail clamps for dividing power districts. A rail clamp for bridges is also offered to make removing bridges easier. For outdoor garden railways, it's highly recommended to use split jaw expansion sections to handle expansion and contraction of straight sections of rail. Power rail clamps can be used in addition to the normal clamps to add power where needed.


Hillman offers a wide variety of clamps that also fit all codes and manufacturers' track sizes and comes in brass, aluminum, or stainless steel. They make a clamp that looks a lot like the split-jaw, but also make a large variety of other clamps. One actually is made to fit over the Aristo joiner to strengthen the joint and increase conductivity. They also make insulated rail clamps, expansion rail clamps, power rail clamps (to connect power to the track), wheel stops, lift out bridge and turnout clamps, adapter clamps for code 332 to 250, bridge hinge kits, and clamps for Tenmille European rail. They also produce an Expando Rail which will take up to 30 feet of expansion due to weather on your outdoor layout.

San Val

San Val sells a system that is called "the Conductor" which is not aesthetically appealing because the screws can be seen on both sides of the joint.

Expansion Sections

The use of expansion track is vital only for the long sections of track. Track on turns and curves are fine as the track should float in and out as the rail expands and contracts. A portion of track that has 20 feet (6 meters) or more should use an expansion section. This prevents track from buckling in the heat or large gaps that the trains cannot cross without derailing, loosing power, or causing extra wear in the cold (winter/night).

Some guidelines:

  • less than 20 feet, you may not need an expansion section, but it can't hurt. Not need until past 10 feet.
  • If you have 20 feet, put an expansion in the middle so you only have 10 feet at most between areas of track that can relieve pressure.
  • Every 20 feet of track for runs longer then 40 feet.


  • 10 feet - None needed.
  • 20 feet - One in the middle of the run.
  • 30 feet - one somewhere in the middle. If one end has a tighter turn into the straight section than the other, place the expansion section closer to the wider turn.
  • 40 feet - One 10 feet in from both ends, leaving 20 feet in the middle.
  • More than 40 - one 10 feet in, then every 20 feet.

See Also