These are links to useful docs. I make no certification that they are current, latest or accurate.
VLS_escort_vehicle_code_of_practice
A_brief_guide_to_overhanging_loads
Conspicuity_for_heavy_goods_vehicles
Chapter_8_legislation_section_5
Washing_instructions for markings
Application_guide for markings
Water Preferred Policy – Guidelines_revised_2012
Notice_requesting_a_Local_Highways_Authority_to_secure_the_removal_of_an_obstruction
Lighting_and_marking_COP_for_abnormal_load_self_escorting_vehicles_HE_rebranding_Ver1