Got curious and looked this up a while back. They’re plastic ducts that hold cables for mostly signaling and some communications systems. They’re pretty common as they were easy to install and helpful for construction crews, but, are slowly being phased out as trains can sometimes sag the track and crush the pipe causing damage to the cable within the duct.
Its orange tubing / pipes thay they use for cables that pass through the four foot. These are so when the teams are tamping the track its easily identifaiable so they dont snag loose cables. Hentis
As stated above these orange pipes are the old method of routing cross track cables. These haven't been permitted for use for years now but you will still see them a lot. I'm a signalling principles design engineer and part of my job is drawing cabling requirements on a layout so that the track design can incorporate cable management sleepers which have cable ducts built in. These usually (not exclusively) take tail cables for points, signals etc and multlicore lineside cables carrying signalling functions between the interlocking and locations. We try to route point tail cables in as short a route as possible in order to reduce volt drop/cable resistance between the N/RWMR relays at the location and the point machine to avoid using larger cabling. It can be a bit of a jigsaw puzzle if you have several lines and other things in the way as I discovered when designing Westbury South in 24/25 with one HPSS point having to use a 35mm² cable rather than the usual 2.5mm² or 10mm²! So when you see an orange pipe someone back in the day probably had to sit and work out exactly where to put it too.
Safe routes underneath the track for greater crested newts. (Britains most strictly protected amphibian).
