When beginning your railway modelling journey, understanding the need for correct spacing for a double track is crucial. From the planning to laying the tracks, you must ensure there is enough clearance between two running tracks. This allows for the safe passing of trains on opposite tracks, which prevents collisions. So how far apart should OO gauge double tracks be?
On actual railways, the spacing of double tracks can differ based on factors like line type, speed, era it was built, buildings, and infrastructure obstacles. The distance between tracks on a layout also varies depending on the modeller's preference. Some modellers aiming for accuracy will strive to match the real-life track spacing. This involves trackwork having wider radius curves to accurately depict the scene being modelled in miniature.
Many modellers lack a large space, so compromises need to be made to accommodate a layout in the space available. Luckily, model railway standard trackwork has a standardised geometry that provides sufficient clearance between trains on opposite tracks. This track is commonly included in starter train sets & track packs, it can also be purchased separately. OO scale standard track, known as regular track or Settrack. Settrack is Peco's brand name for their version of Hornby's standard trackwork. Peco Settrack is fully compatible with Hornby trackwork, allowing for seamless integration of both track systems.
How Far Apart Should OO Gauge Double Tracks Be?
The standard spacing for double track in OO scale, when using brands like Hornby, Peco Settrack, or similar, is 67mm. This measurement is taken from the centre of one track to the centre of the next track, as shown in the photo below.
A great way to begin laying double track is by utilising a pair of points on a crossover as the starting point. Hornby provides both standard points and longer points with a gentler radius, known as Express Points. When used in conjunction as a pair, they create a crossover with the standard double track spacing of 67mm. Peco also offers its own range of pointwork, which provides a wider selection of pointwork compared to Hornby. The Peco pointwork is compatible with Hornby's track. The photo below showcases a double track line featuring a crossover using Peco points in the foreground lower left.
Curved standard / Settrack includes standard radius curve pieces. The likes of Hornby, Bachmann, and other similar brands produce these standard radius curves. The curved track radii are categorised as 1st, 2nd, 3rd, and 4th radius. The 1st radius is the tightest, while the 4th radius is the least tightest. These pieces, along with the points, enable a double track to navigate a curve while maintaining the standard double track spacing of 67mm.
Both Hornby and Peco provide a handy track geometry plan that illustrates the standard spacing for double tracks on straight sections and curves. These plans also include the layout configuration of the point work. You can find both these diagrams below.
Hornby track geometry plan
Peco Settrack geometry plan - with track part product numbers
Peco also manufactures another range of OO scale track work called Peco Streamline. Streamline offers a wider variety of points and flexible track options for both straight and curved tracks. This track is specifically designed to achieve a more realistic, double-track spacing that closely resembles real-life railways. It's ideal for layouts with gentler curves, allowing for closer double-track spacing. However, it is important to ensure sufficient clearance for your longest locomotives/coaches when using this narrower spacing on curves.
How Far Apart Should Streamline OO Gauge Double Tracks Be?
This narrower Streamline double track spacing is 51mm apart, measured from track centre to track centre.
Peco produces a practical track-laying tool called the 6ft Way Gauge. It serves as a useful track-laying jig. It is designed for use on both the standard double-track spacing as well as the Streamline narrower double-track spacing. Additionally, it includes a platform clearance gauge on one end, making it even more versatile. It's worth buying two or three of these cheap jig tools for doing longer sections of track. The image below shows this handy track-laying tool
Peco 6ft way gauge track spacing tool
One important thing to note is that certain types of rolling stock can have a greater overhang when travelling around curves. The Hornby Pendolino and the Rapido Trains APT-E, are two of the longest models in OO scale. Specifically, the APT-E with its very large overhang may necessitate the involvement of your track maintenance teams. This involves modifying your double track spacing on curves to a wider spacing width than the standard spacing. Additionally, adjustments may need to be made to lineside infrastructure to ensure sufficient clearance.