One coastal convoy in the fall of 1940 lost fourteen of twenty-five ships between London and Bristol. The toll on the East Coast convoys was just as great, with the threat of E-boats making a quick dash from ports in the Low Countries. The problem was that if coastal convoys were discontinued, the British rail network could not handle the extra traffic and factories would be idle for lack of raw materials. The vessels used in the coastal trade were small and specially designed for the service, and of limited utility on ocean convoys. The traffic in coal from the northeast of England to London was especially important.