In total there are 16 fences on the Grand National course, 14 of which are jumped twice along the four mile, two and half furlong distance, which is the longest Jump racing distance in the UK.
The fences used to be constructed from natural thorn hedges and were known as ‘thorn fences’. However, they are now created from Sitka or Norway spruce, which is brought down from the Lake District, and it is weaved into plastic birch structure which provides flexibility should a runner make a mistake at the jump. It takes the Aintree Groundstaff team three weeks to build the fences from 16 lorry-loads of spruce prior to the Grand National Festival.
There are many well-known fences at Aintree including Becher’s Brook, Canal Turn and Valentine’s, all of which provide different tests for the runners and rider. Each fence varies in height, with the lowest measuring at 4ft 6” and the highest, The Chair, at 5ft 2” which also has a 5ft wide ditch on the take-off side.