Saturday, 12 November 2011

Tow for the price of one

That's probably one of the worst puns I've ever used as a blog title!

On bonfire night, we'd breasted up with our friend and neighbour Mark on Suzie Q. As his engine (Lister SR2) is awaiting some parts after he and I had a go at curing the uneven revving and hunting, and the massive holes in the exhaust expansion box, we towed him along to Midsummer Common, breasted up alongside, so that we could watch the fireworks from the roof.

This is the first time we've towed anyone else, and so it was quite an experience. We're much more used to being towed ourselves! As Suzie Q is only a foot shorter than the Duck, we decided- for control of the two boats on the short trip along the common- to tow breasted up to the fireworks, but that made the handling interesting.

Although the Duck's engine was powerful enough to shift the two boats happily enough, stopping was more of a problem. As both boats are modern and shallow-drafted, the tendency when putting the Duck into astern to slow the two boats was to pull the combination around and slew it across the river, which was quite annoying. It needed very careful handling, but we successfully got the boats along, and then winded the two. Turning was trickier because of the boats slewing when reverse was applied, but we got around with inches to spare. In the same spot, I can just about get the Duck around in one go, in a U-turn, as the river's 60' wide at that point.

Once we'd watched the fireworks, we cruised back again, as we had to turn around onto the mooring. But we were having so much fun that we carried on past the wider point where we were going to stop and went as far as the Pike and Eel, quarter of an hour down the river, before turning.

On the way back, I decided to try something different. Towing breasted up was OK for short distances, but it wasn't very efficient, as there was a great deal of disturbed water. Our normal cruising speed down the river, past the moored boats, is 1,200 rpm or so (tickover is 800)- but to get a similar speed, the engine was having to work up to 1,800 or so. I decided to try towing on long cross straps for the way home, so that Suzie Q, as a butty, didn't have to be steered, and the longer cross-straps allowed a bit more thrust from our prop. Mark was a bit unsure at first, especially as tying the cross-straps involved untying from his engineless boat in the middle of the river, but it worked out very well. I brought the pair to a stop, untied the DUck, and brought it to the bows, where I put a loop over his T-stud, ran the rope past his stem post, to the opposite dolly on the Duck's stern, took a few turns, round the other dolly, and back to his t-stud to be tied on the other side of the stem-post.

The cross straps are a really ingenious design, often used by pairs of working boats when unloaded. The cross in the rope means that, if the butty drifts off to one side, the pull becomes diagonal and centres it again.

This made towing much easier- we could move at 1,400 rpm for the same speed, so more fuel-efficient!- and we headed back in fine style, with no need to steer the butty boat, even around a few corners. Steering was more of a challenge with two boats- I had to remember that the bow of the butty followed my stern, and then his stern would swing out as we came around, which made the corners an interesting challenge.

A bit like driving one of these, I suppose!

Mooring up was fun, too- we just slowed down in plenty of time and drifted into the gap.

Great fun to practice this technique, when it didn't matter, so that in future we can use it if we need to.

Things I learnt from doing this:

  • Modern, shallow draft boats with high-revving engines and smaller props will tend to pull around to one side, when reversing, as the stern of the motor boat is pulled around. A deeper working boat, with a larger prop and more torquey engine, is much less susceptible to this; when towing the Duck with Warrior, all those years ago, it was never that bad, because Warrior was so deep it resisted turning and liked to stop in a straighter line!
  • If winding when breasted up, make sure you have the butty on the opposite side to your turn- so if the butty is on the left of the motor, turn to the right, so that the slewing effect of reversing the motor's engine works in your favour, not against you as it did the first time I turned. It took ages, and I nearly got the long shaft down and punted them around.
  • If you can, tow on cross-straps, as it's much more efficient- but more of a boat-handling challenge, as you've effectively got a boat that's twice as long that bends in the middle!


  1. James, doesn't the prop walk always push the stern the same way, irrespective of which side the butty is?

  2. I didn't find that, although we only breasted up on one side, so it may well have been acentuated.

    It seems from what I did that the boats together act like a 14' widebeam- only with the propeller right over one side, which gives a very asymmetric pull in reverse, causing the skewing.