Why Length Behaves Differently to Weight
A heavy load tests the trailer and the ground beneath it. A long one tests the road ahead. Overlength cargo does not just occupy more tarmac; it dictates how far ahead the driver has to read the route and how much of the road the trailer will sweep through every corner. A load stretching the length of two trucks turns a bend that any lorry would take without thought into something that has to be planned, walked and, in places, negotiated with whoever else needs the road.
The team has lived with this since long before length became a talking point. A preserved locomotive bought out of Sarajevo brought the issue to the front in an unusual way. The only road out of the city crossed a bridge too weak to carry the load, so the answer was a trailer far longer than the locomotive actually needed, spreading the weight so that only part of it ever sat on the bridge at once. The harder job that followed was convincing every authority along the route to accept a combination that looked far bigger than it had any right to be.
Transporting Wind Turbine Blades: Extra Long Loads Now More Common
We now turn to the question of length. Until the advent of wind turbine blades, extra long loads were very much a rarity, normally associated with long concrete beams, refinery columns, gantry cranes, etc.
In the early days, the length of turbine blades was fairly modest, increasing exponentially with the development of offshore farms, with manufacture taking place at a local port, for direct shipment out to sea. Having said that, STG remains heavily involved in the movement of smaller blades (yet still extremely long) to onshore sites, a case in point being blades from Northern Ireland to France.
Once again, the question of manoeuvrability comes to the fore. To put this into perspective, blade lengths the equivalent of two trucks long are not uncommon (30m+), causing major problems when negotiating even the most standard of roundabouts. Once again, sophisticated steering mechanisms come into play, with a trailer steersman walking behind the trailer, making constant adjustments to the direction in order to avoid colliding with street signs, lamp posts, etc.
