The proposed harbours called for many huge caissons of various sorts to build breakwaters and piers and connecting structures to provide the roadways. The caissons were built at a number of locations, mainly existing ship building facilities or large beaches like Conwy Morfa around the British coast. The works were let out to commercial construction firms including Balfour Beatty, Costain, Nuttall, Henry Boot, Sir Robert McAlpine and Peter Lind & Company, who all still operate today, and Cubitts, Holloway Brothers, Mowlem and Taylor Woodrow, who all have since been absorbed into other businesses that are still operating. On completion they were towed across the English Channel by tugs to the Normandy coast at only 4.3 Knots (8 km/h or 5 mph), built, operated and maintained by the Corps of Royal Engineers, under the guidance of Reginald D. Gwyther, who was appointed CBE for his efforts.