Fire crews have been working through the night to try ensure trains from Exeter to London are running in the the run-up to Christmas day.
Fire crews have been helping to protect the main Plymouth to London train line at Cowley Bridge, Exeter, from the threat of disruption from flooding during the early hours of Saturday morning.
The line was closed during a period of adverse weather at the end of last month after the nearby river overflowed and led to the line being closed.
Following warnings today from the Met Office and Environment Agency, the rail company has requested the assistance of fire crews to help prevent floodwater from damaging signalling at the junction, which could lead to the line closing again.
Four fire crews will construct barriers from around 12midnight to 3am on Saturday morning to help divert water away from the Cowley Bridge junction area.
The actions of the fire crews are designed to keep damage to a minimum to help protect an important part of the south west's transport infrastructure.
The Met Office is forecasting heavy rain across England and Wales over the coming days, with the heaviest rain expected to fall in Cornwall and Devon, and some parts of Somerset. This rain will fall on saturated ground, which is expected to lead to surface water and river flooding.
There could also be run-off from fields and some flooding of property and roads.
There could be as much as 40mm in some locations, and flood alerts and warnings are expected to be issued across most of Devon and Cornwall by early tomorrow.Train lines have already been affected by the weather as flooding is causing disruption between Taunton and Exeter St Davids.
