£2.4 million. Great George Street In 1835 Robert travelled with his father to Belgium. George had been invited to advise King Leopold on the Belgian State Railway and was decorated with the Order of Leopold; Robert returned with his father two years later to celebrate the opening of the railway between Brussels and Ghent. By agreement with the L&BR, Robert was not permitted to work on any other engineering project while the railway was being built, but he was permitted to act as consultant. The Stephenson valve gear was developed in 1842 by Stephenson employees in Newcastle. The six-coupled Stephenson long-boiler locomotive design was developed into a successful freight locomotive but was unsuitable for sustained high speeds. The Stanhope and Tyne Railroad Company (S&TR) had been formed in 1832 as a partnership to build a railway between the lime kilns at Lanehead Farmhouse and the coal mines at Consett in County Durham. The partners had decided to build a railway instead of upgrading the existing Pontop Waggonway, and commissioned Robert as surveyor and consulting engineer, and with Thomas Elliot Harrison as acting engineer, construction started at Stanhope in July 1832, and the line opened in 1834. Instead of obtaining an Act of Parliament the company had agreed wayleaves with the land owners, requiring payment of rent. The company borrowed heavily, and the debt grew to £440,000; by 1840 the lime kilns and the section from Stanhope to Carrhouse had closed, and the remaining Stanhope to Annfield section was losing money. A creditor sent a bill to Stephenson that the railway company could not pay, and Robert found that as the S&TR was not a limited company, shareholders were liable for the debt. Fearing financial ruin Robert sought the advice of Parker, the insolvent railway company was dissolved on 5 February 1841 and a new limited company, the Pontop and South Shields Railway, was created to take over the line, Robert contributing £20,000. The southern section from Stanhope to Carrhouse was sold to the Derwent Iron Company at Consett. The Great North of England Railway opened in 1841 to York with a railway connection at Darlington to London, and the Newcastle and Darlington Junction Railway (N&DJR) was formed to extend this line to Newcastle using five miles of the Pontop and South Shields Railway. George Hudson, a railway financier known as the "Railway King", was the chairman of the N&DJR, and