THE prospect of extra passenger trains between St Albans and London is unclear, and should not be used as an excuse to reject the railfreight project, Helioslough's transport expert has assured the inquiry.

Commenting on the Thameslink infrastructure project's projection of many more trains on the line, he said: “It carries quite a degree of weight. However, the timing of those services is still up in the air. There is quite a window before it can be finalised.”

Helioslough's critics argue there will be not enough space on the main rail line to run goods trains into the terminal as well as an expanded passenger service.

Network Rail, responsible for running the line, has failed to guarantee there will be space, but Mr Gallup said this was not surprising, as it could not know what demand there would be from other train operators by 2015, the earliest the depot could be working.

He added that Network Rail had proposed and planned for a large goods yard on the former Handley Page airfield long before Helioslough got involved.

Asked whether the track was capable of handling large goods trains, he said: “Any change since the last inquiry has been on a positive basis.

“In 2007 the Midland Main Line south of Bedford was W7 gauge.

“The latest route plan shows it is W8.”

He added that DB Schenker, the German rail freight company interested in Helioslough's project, had recently found a way of safely running freight trains nine feet six inches high on a line officially classified as W7.

He said: “In the short term that increases the capacity of a railfreight terminal at Radlett very considerably.”

Mr Gallup's evidence and cross-examination is likely to absorb most of today, although it may be possible for the last witness to start late this afternoon.

After another short debate over possible conditions, the three barristers will give closing statements summarising their arguments.

The inquiry will conclude on Friday by discussing Helioslough's application for costs before inspector Andy Mead returns to his office in Bristol to consider his written recommendation to the Secretary of State.