Sealine F33 Radar Bomber Prop and Safety Line
Swing/Lift bridges on the Broads are notoriously unreliable - especially in the summer. My Sealine F33 is 4.04m (13'3") from the waterline to the top of the ride light (dimension B) below.

However, with the radar bomber down, it only measures 3.05m (10'0") to the top of the screen (dimension D). It's therefore useful to be able to lower the radar bomber, at least until the point it's no longer the limiting factor.

The previous owners don't appear to have had a system to do this, so I had to buy a couple of bits and make a few minor modifications to make this a safe process.

First of all, I found a Bessey ST250 ST Telescopic Drywall Support, Grey, 2500 mm to lower the bomber onto. This has a 60kg rating which is quite suitable for the ~ 20kg weight. The height is easily adjustable.

Whilst this is sufficient and stable enough to support the bomber in its lowered position, I wanted to put a stainless steel cable inside the bomber to act as a failsafe and also to allow it to be lowered or raised single-handed if needed.

I therefore purchased some U-bolts, 4mm stainless rope and cable clamps.

I positioned the lower anchor U-bolt as far forward as I could whilst enabling the nuts to be fastened in the rear canvas locker:

The upper anchor U-bolt is fitted just inside the bomber front edge:

Both anchor points were sealed with silicone sealer during assembly. I lock-nutted the ones on the bomber, cut the protruding excess bolts off, and tidied these up with my Dremmel.

Whilst the safety cable is sufficient to hold the weight of the radar bomber, I expect to still use the support prop whilst underway - it just feels more solid.

Nevertheless, once I'm ready to raise it again, it's quite safe to remove the prop and rest it on the cable before I pull it up.

I spliced and knotted a large eye in a rope to easily wrap around the bomber for lowering and raising:

I haven't measured the final height of the boat with the bomber lowered but it looks roughly the same height as the seat back:

17th July 2021