The Water Tank Trebuchet

Today was water tank replacement day – a day of reckoning for my welded tubular water tank maneuvering device (WTWTMD) – a sort of water tank trebuchet. Lavela and some manpower met at the warehouse and hauled the trebuchet truss to the base of the tower. I spent some time rigging the main hauling rope and brainstorming ideas for hoisting this acute steel triangle with a hook nose up the side of the 30-foot tower. Inevitably, all Liberian roads led to the only logical solution: brute force. I had envisioned some ropes to hoist while others pushed/pulled into position. Nah…skip the ropes and let’s just push/pull. To my amazement (once again) the band of flip flop wearing strong arms got it up the side and interlocked with the rear 2″ diameter steel pipe that formed the guard rail but in my design would act as the “axle” for our pivoting WTWTMD. Hopefully you can decipher what I’m saying by looking closely at this photo (taken just after it got interlocked with that horizontal pipe):

We lashed the WTWTMD to the “axle” with some rope and rigged the old tank to this crooked fishing pole. We were able to hoist it up with a rope from one direction (left in the photo above) while attempting to gently lower it once past the protruding ladder. Unfortunately, it got a little hung up causing the tank to fall enough to jerk the hoisting rope. Although the rope was strong enough, the weathered and now brittle molded attachment points on the tank weren’t. One cracked off leading to a quick jolting fall of about 5 feet which then stressed the opposing attachment point causing it to break too. The net result was a semi-controlled free fall with the tank landing flat on its bottom. Points were awarded for sticking the landing but were quickly lost for poor style. I gave it a 9.9 because the WTWTMD held strong, the old tank was down, and no one was seriously injured.

Hoisting the new tank was quite satisfying as my trebuchet design on paper worked in reality. Check out this video I posted on YouTube (this poor resolution video took me nearly half an hour to upload so you better look at it!!…gotta love the network here). You’ll see me on the tower ladder with my cowboy shade hat shouting directions as the video begins…

The crew burst into applause after it gently landed into place on the platform planks.

After lunch I made the PVC pipe connections and flipped the pump switch to let our solar panels do their thing. As I checked for leaks, I knew the Achilles heal of this entire project would be the cheap fittings provided by the tank manufacturer. Sure enough, water began dripping from the two fittings used to plug standard holes drilled at the factory (which we can’t use). I tried a quarter turn more on one and the plastic nut cracked. I added plumbing dope (thread sealant) and installed a new nut. As I’m lying in bed right now, there’s still a drip from both fittings. Maybe I’ll try again tomorrow,

4 thoughts on “The Water Tank Trebuchet

  1. That’s quite a crew you have there, John, and a challenging task, to be sure. Clicked on the video link and got: “This video does not exist; sorry about that.” Acknowledging my low-tech capabilities, it’s probably me. Be well, Herk


    1. I found if you copy and paste the video in a new browser it works. Glad no one was hurt. I bet this was a great learning experience for all!


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