IanD

I don't think we're disagreeing here... 😉 It all depends which has the lower torque limit, polyvee on vee pulley on the alternator or polyvee on flat pulley on the flywheel. With a big diameter flywheel the alternator pulley will probably set the limit, which is fine (but a 180 degree wrap on the alternator is needed). If the flywheel is big enough then the faster wear due to running on the tips of the belt (about 20% of the area) should also be fine -- but both these should be checked with Balmar.

The vees on the belt sitting in the vees on the pulley increase the frictional force for a given belt tension because they're at an angle, the steeper the angle of the sides of the vees is the bigger the increase in the torque capacity at a given belt tension. The factor is 1/sin(angle), so 2x if the sidewalls are at 30 degrees to vertical. If you run the polyvee belt points-in on a flat pulley you don't get this advantage, just increased force per unit area on the belt tips (maybe 5x?) which will increase the wear rate compared to a flat belt.

I'd still much prefer a tiller to the wheel my hire had -- yes you could see along the side, but it was very slow to steer with no feedback feel of the tiller angle (except looking behind you at a small pointer on top of the rudder). Wine, beer or gin consumption -- or all three... 😉 I'd say 3mph (20mins/mile) is too optimistic for a wideboat along this section based on my experience (it's OK for a narrowboat). 14mins/mile for walking is also quite brisk for most people... (but still, that trip will be fine for a day in June with 4 adults) When we did that stretch a couple of the swing bridges were absolute sods to move, pretty much impossible for one person (me) -- maybe they've been fixed by now, or 2 people might be needed... If you're in Skipton overnight the Beer Engine is highly recommended... 🙂

You don't want a very long unsupported belt run between flywheel and alternator anyway, it can make the belt prone to vibrating/resonating from side to side (like a plucked string) driven by engine torque fluctuations -- especially with a big (heavy) alternator spinning quite fast, which has a lot of inertia. FYI Beta recommend using a freewheeling pulley with big alternators like this to reduce vibration and belt wear, but these are only available in certain sizes (diameter and V count).

15 locks in a day -- even wide ones -- isn't a problem if you've got a crew big enough to have several operating them, which I assume you have?

If the alternator is 24V 140A then that'll be about 4kW output, which means about 7kW/9hp input, which is a *lot* -- make sure this doesn't overload the engine, you'll probably need an alternator controller like the Wakespeed which pulls back current at low rpm. IIRC Balmar specify a 180deg wrap, if you don't have an idler pulley with their standard (6-rib?) polyvee pulley you risk it slipping -- see picture above for a recommended layout.

We hired a 58' x 10' widebeam (how big is the one you're hiring?) on the L&L a couple of years ago, and you definitely can't travel at the same speed as a narrowboat either in open stretches of canal or passing moored boats, because a widebeam displaces a lot more water. I'm used to always travelling faster then canalplan estimates on a narrowboat, but found I was travelling slower than estimated on the widebeam. It's not the locks that are slower (though you can't share, obviously...), it's the bits in between.

Which means an idler pulley is needed, like this... (alternator is a 48V 100A Electrodyne)

But then you might get slipping on the flywheel side (no grooves), the tension in the belt is the same at both pulleys -- you might be lucky though because the flywheel is so much bigger diameter. Even without this, a polyvee belt running on the tips of the vees on the flywheel is likely to wear them away quickly... 😞

If you use the smooth side of the polyvee the power it can transfer will be much smaller than using the grooved side, the angle of the vees increases the torque that can be transferred by several times (2x-3x is my estimate depending on vee angle). This will make your problem of getting power into the alternator even worse, it'll slip on the alternator pulley.

Thanks for helping out -- just spoke to Dave on the phone, sounds like a nice guy, all sorted 🙂

Got a quick response to a text, Dave said there should be space next spring after winter boats leave 🙂

I'm a few years short of that too -- but not that many... 😞

Times have changed though. The daily multiple-pint drinkers who used to keep pubs open -- often heavy manual or factory workers -- have largely disappeared, and eating out is much more common nowadays. Pubs need to cater to the clientele they have today, not the one they had 50 years ago...

Cars with high-power xenon/LED lights are legally required to have self-levelling to prevent dazzle... It's possible that the dazzle culprits are drivers who have retrofitted LED bulbs to old headlights, which is also illegal but this doesn't stop people doing it... 😞

Thanks, I've got the number now 🙂