What a great idea!

I’d never heard of this method of tunnel construction.  Odysseus, who first posted it at his blog By Other Means, called it ‘Grown Up Lego‘.  That’s not a bad description.

I wonder if the truck has to be left in that configuration permanently, or whether they can dismount or uncouple the tunnel-shaped thingamajig to use the truck for normal work, then reattach it when it’s needed once more?  Also, can the same technique be used for larger or smaller tunnels, or is it basically limited to what can be fitted to the truck?  If anyone knows the answers, please tell us in Comments.



  1. The truck is a standard flatbed with their roller form loaded and chained down. I presume you could build any sized tunnel you had the blocks and form for as the angle on the blocks and the size of the rollerform would change as size changed . If you look the form is tapered rom larger in front to smaller in back , Thus it holds the arch open while the keystone is dropped in place and then sets everything snug as the truck is pulled forward .

  2. Impressive, though just a modernized form of the method developed by the Romans (who built wooden scaffolding/forms under their arches) and improved upon by medieval Europeans for their Gothic cathedrals.

  3. Very nice! I'll note though that all that went together very quickly, not sure you'd WANT to take the time to unhook and rehook the truck. Although its hard to tell of course in an edited video I doubt that whole thing actually took very long at all once they actually got to the point of needing the truck. According to their website "With it, 1.5m of arch can be constructed every 5 minutes!"

    They also say that it can all be done using counterweights, so you're NOT limited by the size of the truck, and it can infact be built over waterways etc.

  4. Peter, apologies for the off topic, this video is from 2007, yet still an interesting helo modification.


    I have no idea how far the cg moved, because of the weight difference between the original tail and the new one, but will guess it's still within the original design limits, otherwise the helo wouldn't lift.

  5. I've never built one with a truck under it before. These are not new. This type of arch is usually used for low head clearance, small volume situations. Especially golf courses or bike trials. I've only used the Traveling Form with adjustable feet. But anyway these are fun to build, Legos for adults.

Leave a comment

Your email address will not be published. Required fields are marked *