In fact the company found it impossible to raise the huge capital needed for such a scheme, and it settled for a line between Colwick (a few miles east of Nottingham) and Grantham, where it connected with the Great Northern Railway.

The Corporation of Boston was dismayed at this and appealed to the Ambergate Company in August 1847 "to complete their line with as little delay as possible.

"[1] The appeal was made in vain and the Ambergate company opened its line west of Grantham only, in 1853.

The line to a temporary terminus there was opened to the public from Sleaford to Barkston Junction on 16 June 1857.

[7][8] The second part of the line was inspected by Captain Tyler on 31 March, but he was not satisfied, requiring the electric telegraph to be installed, the junction and signalman's stage at Boston to be completed, clocks at stations, a ballast pit near Sleaford to be fenced, contractors' gear removed, a safe method of working to be determined by the GNR, and iron spikes instead of wooden trenails used to secure chairs to sleepers.

[8] An exchange station at Barkston was opened at the junction on 1 July 1867, to facilitate passengers' journeys from the Newark direction for Sleaford and Boston, platforms being staggered on either side of the level crossing, separate from the down main line and branch.

[9] By an Act of 28 July 1873 the GNR obtained powers to construct the Sedgebrook and Barkstone Junction line.

[10] This was built with the main aim of simplifying the movement of coal from Nottinghamshire to Lincolnshire without reversal at Grantham.

However on 10 January 1874 a passenger train from Boston overran signals at that junction, and fouled the path of an up Scotch express.

[12] From the summer of 1903, there was a GNR West Riding express from Leeds to Cromer and Yarmouth using the north curve.

In the Sleaford area this was a new railway, although it connected at its extremities with pre-existing lines which were now placed in the joint control and ownership.

The line was designed for heavy mineral flows from the Yorkshire coalfields to London and East Anglia, and a bypass (avoiding) line was built for Sleaford to avoid conflict with ordinary traffic; a connection was built at each end of Sleaford to enable trains on the Joint Line to make station calls at Sleaford.

[20] Passenger services on the branch to Cranwell RAF College ceased in 1927, followed by those to Bourne on 22 September 1930.