When, in 1858, the Midland trains began to run over the Great Northern metals from Hitchin to King’s Cross, the Midland management regarded their trains as providing a main line service. Unfortunately there were only two tracks in this section of over 31 miles, and the Great Northern were beginning to fill these tracks with their own trains. The Midland, despite the sum of ￡60,000 a year which they paid the Great Northern, were coming to be regarded as a nuisance. In 1860 James Allport (later Sir James) had returned to the Midland as general manager, and he was not one to allow his company to exist as a second best. The junction at Hitchin was under the control of a Great Northern signalman, and his instructions, to say nothing of his loyalty, caused him to give preference to the trains of his own company. In 1862, the year of the second Great Exhibition in London, the delays assumed gigantic proportions, and 3,400 Midland trains were delayed between Hitchin and King’s Cross. Of this total, 2,400 were freight trains, many carrying coal, and when on 30th June the Great Northern refused to allow Midland coal trains to stand in their sidings at King’s Cross, it was inevitable that the Midland would decide to build their own line to London. They already had their own coal depot at Agar Town near St Pancras.

When the Great Northern saw that they were likely to lose ￡60,000 a year, they at once offered to quadruple their line between Hitchin and London. Allport countered by asking for running powers in perpetuity, The Great Northern offer was only a palliative in view of their own growing traffic, and Allport was only ‘playing trains’ while pushing on with his real objective - the Midland Railway London Extension. Liddell and Barlow, competent engineers, plotted the route, and the Midland Board had little difficulty in convincing Parliament that their line was essential. The Bill became law in 1863. If there was any doubt at all in the mind of the Board that they were doing the right thing, such doubt was removed by the Welwyn accident of 9th June 1866.