BIGGEST WALL OF DEATH IN THE WORLD
‘We’ve built it. It’s down to Guy now’ GUIDE TO THE WALL OF DEATH Doors The key thing when designing the doors was that we have to be able to get Guy out within 40 seconds. So we have people training to open them as fast as possible. The doors are desig
Chris is a structural engineer tasked with designing the wall – he specialises in unusual projects. The tricky thing about designing this is that there is nothing to go off. I visited Ken’s wall, but it is a lot smaller and his riders travel at a slower speed so the design doesn’t translate to our wall. That makes it interesting because we had to start from scratch. Here’s how we did it…
We were given the maximum weight of the bike and rider (320kg) before anything else. So once we had that figure we could design the wall and specify everything to match. But first we would have to work out the maximum wheel load using that total weight figure.
The bike stays on the wall due to centrifugal acceleration (mass x velocity, squared, divided by radius), which gives us the G-force Guy will feel. We’ve upped it to 8.5G to give plenty of room. Using that figure we can get the wheel load by multiplying the G by the weight of the bike and the rider, which equals 2.72 tonnes. Two thirds of that gives the max weight of one wheel, 1.8 tonnes. And then we’ve rounded that up to 2.3 tonnes to be well on the safe side. So now we have the maximum G-force, weight of bike and rider and wheel load. So all we have to do is make sure every single point on the wall can cope with that pressure. We tested that out by using a telehandler fitted with load sensors to push against random parts of the wall and make sure they can all cope with 2.3 tonnes of pressure.
We know we can design a wall that can take the forces. We tested the wall, it’s good to go. The big question is what happens when Guy tries to ride it. It’s down to him now. We wanted something large and bulky that already existed for the shell as we didn’t want to have to build a giant frame for one show. I was helping my dad move
stuff into a shipping container when I realised that all we had to do was turn one on its end. So we used 48 containers with two containers with doors at either end for the shell. The front face is welded top and bottom and the back is tied together with
container locks and studded bar.
Structural grade C24 soft wood. It’s strong timber used in house construction. Imagine those cradles you
stick underneath wine barrels to stop them rolling away; we have a whole series
of those that fit on to the base of the containers to give them the curved form. Each plank is screwed down to them and to the containers. There are no sharp edges. The more people standing on the structure, the more
stable it is.
• •1.5 miles of wooden planks were used
Add up all the metal and it’s just shy of 100 tonnes, plus the wood...
It’s 3.8 times bigger than the standard Wall of Death used by Ken Fox If you go to Ken Fox’s traditional wall
you will feel it shaking because it’s lightweight and portable. This one is a lot more stable thanks to the shipping
containers tied together in one big ring, making it incredibly strong for the
higher speeds Guy needs to reach.
Ken’s wall is in diameter while Guy’s has a diameter, making it
nearly four times the size.
Most importantly, Guy’s wall can support much higher loads. The forces on the wall will be double the forces
placed on Ken’s portable wall.
Guy has two angles on the base. Ken’s has one 45 degree angle, which is fine if you don’t have to change speed often, but Guy will have to reach 55mph
before sticking to the vertical wall so will need to build up speed more slowly.
The seating has been adjusted to create a sit up position which is much further forward than on the standard Scout. The saddle itself has been replaced by a 1920s Scout design. The pegs have been ditched in favour of mid-mount
footplates. Billet aluminium sections have been used in place of the standard shock absorbers to create a traditional rigid frame. Geometry remains the
same, just rigid. Instead of one down and five
up, it’s now a race-pattern shift, so first is up and five are down. This makes it quicker
and easier to change gear while riding the vertical wall. The front brake has been
removed so there’s no chance of accidently grabbing the lever. The back
stays standard. Must be able to smoothly transition onto the wall. A standard profile has a bit of an edge to it, so Ken Fox shaped and smoothed off the edge of
the tyres with a hand-file.
The fork is now a solid down tube with all of the suspension components removed to stop suspension bob caused by the
G-forces on the wall.