Building up the Grand National fences is a full time job led by Head Groundsman Mark Ainsley
The giant Aintree fences are what makes the Grand National such a spectacle and endurance test.
Making sure Becher's Brook, The Chair and the other 14 fences are maintained ready for the big race is the job of Head Groundsman Mark Aynsley.
"It's strictly full time," Mark says of his role at the course which has only nine race days a year.
Mark has worked at Aintree for three years and is responsible for building the different fences at the course.
"We've got three types [of fences]. There's the hurdles which get jumped, they're the smaller ones, we'll repair them in house," explains Mark.
"The chase jumps are made of birch, they're four foot seven high, we'll rebuild all of them every year because the birch becomes old and rotten.
The height of the Bechers Brook fence in 1907
"Then there's the National jumps which we have to build twice a year.
"They're permanently sourced but then we construct on top of them with spruce.
Much of the spruce is transported from Grizedale Forest in the Lake District several weeks before the race.
"The Chase jumps are made of bundles of birch and all that you can see is taken out of the frame in the ground and is then replaced with about 600 bundles of birch in each one and it's pulled tight with a tractor. Then a hedge trimmer cuts it down and shapes it," Mark said.
In recent years the fences have been changed to make them safer for horses and riders, but Mark says they're still a formidable obstacle.
"The height of the fence in reality may have come down only a couple of inches, it's actually the internal part which has come down considerably.
"The part which they jump is loose and it's safe, it's the bit underneath that is a bit harder, so that has been reduced dramatically in height.
This year's long cold winter has taken it's toll on the Aintree course which has had less time than usual to recover and grow back.
"If you walk across the track you might notice the odd baldy spot from the November racing, the winter has significantly held back the grass growth," Mark points out.
The Aintree fences offer a stern test to horse and rider
"We raced at the back end of November and I think it snowed a couple of weeks after that and last week we had the last of the frost, so the growing window to get the grass ready for the National is short.
"It's been fed, it's been over sown, we may well sheet up the whole bit just to warm up the grass and get the germination a little bit better."
Getting the course ready for racing is just one of the tasks facing the Aintree authorities at a site that is used year round for many activities.
"We had an inspection by the British Horse Racing Authority Inspectorate, they'll go around and they'll check the rail the grounds, the going, the fences, all aspects, stables, the lot," Mark said.
"You'd be surprised at what goes on here from equestrian events in the International Equestrian Centre, they have concerts and exams, and it will be a giant bar shortly for the National.
"There's motor racing, motorbikes, we have football pitches on site.
"It's a fantastic site so why not use it."