 The Chattenden and Upnor Railway was originally laid in 1873 to gauge, as a training exercise for the Royal School of Military Engineering which was then based at Chattenden Camp.The line ran from Pontoon Hard by the River Medway and climbed steeply towards Chattenden where in 1877 the War Office built a set of gunpowder magazines.A spur led from Church Crossing to the Lower Upnor Ordnance Depot and until 1895 a branch ran from Chattenden to Hoo.