They look like so many asparagus fronds. There are eight long rows of them, stuck into holes in the top of a green box, suggesting garden centre rather than racecourse, but they form the new core of what is supposedly one of the most challenging obstacles in sport, a Grand National fence.
Their appearance at Aintree must count as the most dramatic break with tradition in the history of the famous race, first staged in the 1830s. For the next running, five weeks from now on 6 April, the upright wooden posts that have long formed the solid middle of each fence will be entirely absent, to be replaced with those fronds of plastic birch.
The aim is to reduce the risk of injury to horses and jockeys, following four equine deaths in the past two Nationals. In particular, it is hoped that we may see no more of an especially horrible species of fall, known as a "rotational", caused by a horse's back legs hitting the fence's take-off side. Up to now, with very limited give in the obstacle, the collision would sometimes fling those hind legs up in the air, so that the horse's whole weight would crash to earth on top of its head or neck.
"If a horse does trail a leg here, it will not be suddenly stopped, it will be slowed down," says Andrew Tulloch, who serves as Aintree's clerk of the course, meaning he is responsible for the track's layout. Giving the Observer a sneak preview of next month's new fences in construction, he explains that the plastic birch will be topped with 14 to 16 inches of the familiar spruce, so that each obstacle will be as big and will look exactly the same as last year.
The plastic birch has never been used on a British racecourse, save when it was trialled in two fences here in December. It is commonly used at training centres in schooling fences. The Aintree version will be slightly stiffer than most of those, but Tulloch says it will certainly bend and part if struck by a 500kg racehorse travelling at speed, in a way that the old posts could not.
Fewer fallers should be one result, though another might be that the National field goes faster, the jockeys having rather less respect for the fences than before. Speed is a problem, since any fallers then hit the ground with greater force. Tulloch points out, however, that there is limited scope for the field to go much faster and in any case he has hope that today's generation of jockeys are rather more keenly aware of their responsibilities than those who went before.
Some of those who watch from the grandstand are less keen to move with the times. Each modification to the course over the past 20 years has been met with wails of protest from those who hark back to the days when one jockey famously spoke of Aintree's "bloody great green stone walls".
The only reason there has not been greater protest at the latest change may be that the news slipped out quietly around a month ago. Tulloch feels he can cope with whatever backlash eventually comes his way.
"There is a test about it but it needs to be a fair test," he says. "I think, like everything, things move on, new materials have become available. The essence of the race is the same."
While the old school is not yet hopping up and down, it might equally be said that Aintree has not yet been given due credit by some of those who have been pressing for change. Tulloch says the course has spent more than £1m over five years on various measures aimed at improving safety for the race's participants.
Those include a dedicated washdown area to cool the runners after the event, which will now benefit from technology used at last year's Olympics, designed to fill a large tent with a cooling mist. Also, Aintree has completed a fully automated irrigation system that goes right around the two-mile circuit and will allow Tulloch to water the course on race-morning if need be.
More will be done to round up those runners who have somehow become parted from their jockeys. There will be three mounted helpers; Tulloch resists the word "outriders" that was used when this was trialled in December, on the grounds that it suggests so many cowboys racing along on the edge of the pack, gallantly trying to lasso the loose ones.
Their role will be more in the way of herding and coralling, rather than catching, which, when attempted from horseback, can often result in just one more loose horse.
Tulloch says that part of their value lies in the fact that a loose horse will often stop and approach another horse when, if presented with a person on foot, it might be more inclined to run through them.
Even the three open-ditch fences, notably the famous Chair in front of the stands, have been softened, though their core will be made of real birch, not plastic. Those fences do not have the sloping take-off side of the others and must therefore be wider in order to support the spruce, wider than can presently be made in plastic.
Tulloch sees all of this as a natural progression, rather than a kneejerk response to the media flak following the last two Nationals. "We're always looking to improve it and not stand still. From my perspective, the welfare of horse and rider is the single most important thing.
"For the last five or six years, we at Aintree have been keen to look at an alternative. The problem was finding something that would work and give us longevity.
"The plastic will hopefully last a few years and, with the open ditches, we'll see. If this works, we'll stay this way."
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image: © Paolo Camera