If we're going to build a new Nuclear Power Station at Sizewell, we must Mitigate Construction Impact.

"OK... so if we're going to build a new 'Sizewell C' reactor, then one of the first things to do is to construct a spur off the Aldeburgh Branch Line near Leiston, to enable deliveries, servicing and waste removal by rail for units A, B and C," he said.

A simple equation based on a series of experiments from the 1950s still serves as the rule of thumb for estimating road damage - and it's a fourth power relationship. This means that as axle weight increases, road damage goes up very fast indeed.

To get an idea of the relative rate of road damage you look at the axle load of vehicle 1 and divide it by axle load of vehicle 2. You then get a number which you multiply by itself, and then you multiply that number by itself, ending up with the ratio to the power of four.

Say a 2 ton car has 2 axles - that's 1 ton per axle (½ ton per wheel of course). And a 40 ton HGV has 8 axles - that's 5 tons per axle. (the axle load). Then to get a rough idea of the extra damage from the HGV relative to the car you start with 5 and divide it by 1 - which equals 5 of course. Then you multiply 5 x 5 to get 25 and then multiply 25 x 25 to get 625. (you see, it does go up fast!)

This tells us that the damage potential of an HGV axle load is 625 times greater than that of a car axle.

Of course an HGV has at least 8 axles and the car usually has 2 axles. So taking all the axles into account in our example we find that the damage potential of an HGV is [625 x (8/2) = 2,500] is very roughly 2,500 times greater than that of a car. ("Vehicles don't always have axles", we hear you say. OK, but it works for wheels as well.)

The amount of heavy construction materials needed for Sizewell C will be enormous and will be delivered over a decade or so. We need to mitigate this by putting a rail link into the site.

Based on "Inside Science" website - but NB US "pavement" = UK "carriageway" or "roadway". Image pixabay public domain.