A train came within metres of hitting a one tonne metal pile which had been left between the tracks.
An investigation by the Rail Accident Investigation Branch (RAIB) found a 'lack of clear process' and 'time pressures' had contributed to the incident which happened in May.
The train, a piece of track maintenance equipment, was travelling at around 15mph when the driver spotted the five metre long pipe. The line was open to passenger trains when the incident occurred at just before 5.15am but services had not yet commenced.
The metal structure was removed from the Blackpool-bound tracks before trains were allowed to run.
The report says: "At around 05:14am on Monday May 15 a tamper, which was travelling to leave an engineering possession, encountered a large tubular steel pile obstructing the track near Kirkham North Junction, north-west of Preston.
"The driver stopped his tamper a reported 15 metres short of the pile.
"The pile, measuring 610mm diameter and five metres long, and weighing around one tonne, had been left on the track on completion of earlier engineering works. The work site had however, been given up and declared safe for the passage of trains."
The RAIB report found that crews working to install foundations for overhead power line supports had encountered a number of problems during their shift.
The pile in question had been abandoned on one of the main lines and effectively forgotten.
The report said: "Piling operations commenced with one pile being successfully installed.
"A second pile was not installed because a survey of the site revealed the unexpected presence of buried electrical cables.
"The team then moved to another site but were unable to install a pile at that location because the supervisor did not have the necessary information about the trial hole.
"The vehicle then moved around 50 metres to a third location with the pile intended for the second position still attached.
"The crane controller reportedly instructed the machine operator to put down the pile that was clamped in the piling attachment so that the correct pile for that location could be picked up and installed.
"The operator drove around 20 metres beyond the installation site and put the pile down in between the rails. He then picked up the correct pile for the location and began to install it."
The report shows that although paperwork was signed to state the line was clear of all construction equipment, neither the contractors Volker Rail or sub contractors J Murphy had a clear plan to ensure that was the case.
The report said: "The Rule Book does not clearly specify who is responsible for physically checking that the line is clear of obstructions.
"Although the Work Package Plan (WPP) produced by Volker Rail for the work stated that upon completion of works ‘any plant and redundant materials should be removed from site’, it also did not specify who was responsible for this."
In addition to highlighting the flaws in the plans for the site the RAIB said better lighting might have prevented the incident from happening.
The report states: "Better lighting of the site of work might have reduced the likelihood of the pile being forgotten. The WPP had identified risks with working at night and specified the use of tower lighting at worksites to illuminate work areas.
"However, the piling operation was lit only by lights on the vehicle.
"This meant that staff were unlikely to be able to see the pile left in the main line when they left the site."