How do they go so slowly?

[Wanderer Vagabond]

For the second time in a week I've found myself behind a chronically slow boat and I'm getting curious just how people can go so slowly.Now I am in no particular rush and on the first occasion, 10 days ago on the GU near Nether Heyford I just moored up for the day and left them to it. Today I caught up with another boat going at the same speed (slooooow). Now running my boat at the slowest it will go (about 900rpm on the tachometer, less than 2mph on the satnav) I just repeatedly kept catching up with them. The only 'solution' was to run in gear for a bit, then knock into neutral and drift for a bit and keep repeating (which gets a bit tedious). The query is just how do boats go that slowly (less than half my tickover speed)? Do they fit them with tiny propellers? do they have specially low gears in their gearbox they can change to? how do they do it? (and why).

[mrsmelly]

Not much pitch on the prop and or small prop. Some hire fleets deliberately fit smaller props to mean they run faster to ensure battery charging as thats the usual call out problem of flat batteries and its to try and negate that. Some gearboxes are 2 to one and some 3 etc etc.

[Alan de Enfield]

4 minutes ago, Wanderer Vagabond said:

how do they do it? (and why).

You are asking the wrong question.

 

The question should be how can any boater stand with a 'fixed' view forward, never be considerate enough to see what is going on behind and 'wave you passed'.

 

It is those sort of people who have never had an accident in their car but have seen any number in their rear view mirror.

3 minutes ago, mrsmelly said:

Some gearboxes are 2 to one and some 3 etc etc.

 

Our Boat was ex-hire from Welton, it had a 3:1 gearbox on the Lister LPWS4 which meant it was rev-ing quite fast (and noisy) at cruising speed.

[TheBiscuits]

 

Morse lever setup.  There's usually an early engage and a late engage position for the gear cable, and nearly every boatbuilder uses late position at higher revs so the boat feels sprightly.  I have changed dozens of them for people who don't like being shouted at for going too fast in tickover.

 

@mrsmelly is correct that smaller propellers make a difference, but my boat is configured for "Stealth Mode" so can creep past boats at 750 rpm at about 1 mph.  Beta 38 with a 17 inch prop and a hospital silencer.

 

One of my favourite tales is when we were creeping past a boat late one night and could see a lady washing up.  She didn't hear us, she didn't see us until she looked up, but when she eventually saw our boat boat she dropped a plate in the sink and broke it, and we could hear her swear over the engine noise!

6 minutes ago, Alan de Enfield said:

The question should be how can any boater stand with a 'fixed' view forward, never be considerate enough to see what is going on behind and 'wave you passed'.

 

That's one of my pet hates.  It's also why I use a proper marine horn, as that at twenty feet tends to make the steerer look behind them!

[Arthur Marshall]

And what is also weird is that when you DO get past one of these slow boats that have had you in and out of gear for miles, you don't leave them behind.

I have a theory that there's a slipstream affect in the canal so the boat in front pulls you along faster than you think, same as it does in traffic.

ETA a car or lorry in traffic, that is, not a boat. That would be silly.

Edited October 12, 2020 by Arthur Marshall

[Cheshire cat]

We followed a very slow Black Prince boat two weeks ago. I know that if they want to Black Prince hirers can leave me for dead. We were on tickover  for four hours.

Next morning I was up with the larks because I didn't want to be stuck behind them and miss my 12 o'clock tunnel slot . It turned out they were on the same passage but didn't turn up until ten past. 

 

Luckily for them the fire and rescue team were doing a bit of training at the north portal so there was a half hour delay before our transit started. They still did get a ticking off from the tunnel keeper though.

[Rebotco]

I have this problem all the time on the west K&A.

Stuck hour after hour behind a snail "boater".  So slow a queue builds up, none of them able to steer properly, and little or nothing in the way of recharging the batteries.  Half the time out of gear and the rest at less than tickover.

Absolutely gormless boat at the front totally oblivious to the mayhem he is creating behind.

Even lacks the wit to pull over, just hogging the centre of the channel all the way.

Mostly hire boaters or one of the continuous moorers venturing out into unfamiliar territory.

Usually I have to moor up to avoid canal rage getting the better of me.

[dmr]

Yeah, we can go slow when it suits us, the Beta JD3 sounds almost proper at tickover but a bit harsh when it goes faster, and we are often scraping the bottom too, so slow is good. A few years ago we followed a hire boat, it was their last day and they were determined to get the boat back at the very last minute to get best value for money. I reckon they were doing less than 1/2 mile an hour, they had a crowd of good musicians on the cruiser stern so we made no attempt to get round them.

 

...............Dave

[Mike Richardson]

I have to confess that Kingsbridge isn't the fastest of boats. A Beta BD722 coupled to a 2 to 1 gearbox and a 13 x 9 propeller means we have several choices, We can run at a comfortable 1800 to 2000 rpm and average 2.7 - 2.8 mph which doesn't seem to hinder following boats much (We always wave on if someone wants to pass) or we can run a little faster at 2200 - 2500 which, while vibration-free, makes life less restful but does take us up to 3.1 -3.2 mph. On the Weaver I can just about get the engine up to 3400, so it appears to be the right prop. On one occasion even we had to go down to just over tickover to follow a hire boat the last three miles into Middlewich on the T&M. My GPS on that occasion was showing about 1.5 mph. 

 

We hired on the Mon and Brec some years ago, and that was the slowest we have ever travelled, mostly down to a lack of depth I think. So it's quite possible to travel very slowly indeed if you have the inclination. However, I always try to be aware of what's approaching from behind. I'd much sooner have the speedy boats in front of me,though, it's much less stressful.

[TheBiscuits]

7 minutes ago, Rebotco said:

Usually I have to moor up to avoid canal rage getting the better of me.

 

That's the other option to the horn signal.  Stop and have a brew!

[Rebotco]

6 minutes ago, Mike Richardson said:

 

We hired on the Mon and Brec some years ago, and that was the slowest we have ever travelled, mostly down to a lack of depth I think. So it's quite possible to travel very slowly indeed if you have the inclination. However, I always try to be aware of what's approaching from behind. I'd much sooner have the speedy boats in front of me,though, it's much less stressful.

Much less stressful for the "speedy" boaters too!

[ditchcrawler]

Last week we were dropping down to Middlwich and were fifth in the queue at Bothlane top lock. We were told it was due to the hire boat at the front who had moored on the waterpoint at Wheelock all afternoon and night was on a go slow. The reason the boat following had told him he shouldn't moor on a water point which lead to a barny and hissy fit.

[Wanderer Vagabond]

1 hour ago, Mike Richardson said:

I have to confess that Kingsbridge isn't the fastest of boats. A Beta BD722 coupled to a 2 to 1 gearbox and a 13 x 9 propeller means we have several choices, We can run at a comfortable 1800 to 2000 rpm and average 2.7 - 2.8 mph which doesn't seem to hinder following boats much (We always wave on if someone wants to pass) or we can run a little faster at 2200 - 2500 which, while vibration-free, makes life less restful but does take us up to 3.1 -3.2 mph. On the Weaver I can just about get the engine up to 3400, so it appears to be the right prop. On one occasion even we had to go down to just over tickover to follow a hire boat the last three miles into Middlewich on the T&M. My GPS on that occasion was showing about 1.5 mph. 

 

We hired on the Mon and Brec some years ago, and that was the slowest we have ever travelled, mostly down to a lack of depth I think. So it's quite possible to travel very slowly indeed if you have the inclination. However, I always try to be aware of what's approaching from behind. I'd much sooner have the speedy boats in front of me,though, it's much less stressful.

The set up of your boat does seem to offer an explanation of how to get such slow speeds. My normal cruising rpm according to the tach is 1600 rpm which will give me between 2.9 and 3.4 mph dependent on the depth of water. If you were running at 900 - 1000 rpm (given that 2000rpm seems to give you 2.8 mph) then I would guess that your speed would be well below 2mph, such as our boat today, whereas 900rpm on mine gives me about 1.9 - 2mph.

 

As I said in my OP I'm in no rush and if I find myself travelling at tick-over whether behind a slow boat,or past moored boats, so be it, it is just that when speed goes below tickover it starts to become a PITA rather than a pleasure. Constantly kicking from drive into neutral and back again can't be doing the drive plates much good.

 

I would have to say that if I were in the position of travelling that slow, either through choice or engine defect, I would certainly be looking to wave anyone going faster than me past so there is a slight element of irritation when others don't do the same, but then if someone is travelling at a speed at which I can just run the engine at a constant speed I'll be content just to remain behind them. 

 

 

[cuthound]

As others have said, it is often due to the size and pitch of the prop.

 

When I bought DQ, a 60 foot clonecraft on an Alexander hull, she had a 17" x 11" prop. Tickover speed according to my Ullysse Speedometer app was 1.6 mph at 800 rpm. Normal canal cruising speed was 3 mph at 1500 rpm.

 

The only problem was a distinct lack of stopping power (she weighs over 16 tonnes).

 

Last year I changed the prop fpr an 18" x 12" and it has transformed the ability to stop, without changing the tickover and cruising speeds much.

 

Tickover is still 800 rpm, but now at 1.8 mph. 3mph now equates to 1300 rpm, so slightly more relaxing. She seems to use less fuel as well.

[Hudds Lad]

you'll always catch a slow boat due to slipstreaming, turbulent flow, laminar flow, fluid dynamics and all that other good stuff i never paid attention to in Science due to a lovely girl called Lorraine sat on the next desk being quite the distraction  

[nicknorman]

Unfortunately some people think that going as slowly as possible on the canals is some sort of virtuous act. They pass their day (after all, the scenery barely changes) by reciting the mantra "You mustn't rush on the canals".

 

Actually the real reason is that they are inadequate pathetic people who get a sense of power by forcing other people to follow them at their pace. It is the only time they get to feel "in charge".

[Athy]

3 minutes ago, Hudds Lad said:

you'll always catch a slow boat due to slipstreaming, turbulent flow, laminar flow, fluid dynamics and all that other good stuff i never paid attention to in Science due to a lovely girl called Lorraine sat on the next desk being quite the distraction  

If she was sitting on the desk, I suppose she would be prominently in view, yes.

[Hudds Lad]

1 minute ago, Athy said:

If she was sitting on the desk, I suppose she would be prominently in view, yes.

the desks were in a sort of H configuration, some down the side of the room and some across the middle, she was on the side bench in my peripheral vision, liked to have that extra button undone and bit her pencil a lot.

Mr Holdsworth was a good teacher, but not THAT good.

[Keeping Up]

When I planned my setup, I started from the fact that on open water I wanted to reach 7mph at the engine's maximum revs, ie 400 rpm per mph; so on open water at 800 rpm tickover I am doing 2mph. On a canal I found that the ratio increases to 450 rpm per mph, so at tickover I am doing about 1.75 mph (how do you type three-quarters).

 

This is using a 3:1 gearbox to an 18x14 prop. The slower turning by using 3:1 gives better ability to deal with any rubbish on the blades (the rubbish is moving slower through the water, and there's more torque to push it too).

 

Where appropriate I often lift the throttle slightly to pass moored boats at nearer 2mph, but if moorers hear of it they will usually shout at me to slow down.

[monkeyhanger]

24 minutes ago, Hudds Lad said:

you'll always catch a slow boat due to slipstreaming, turbulent flow, laminar flow, fluid dynamics and all that other good stuff i never paid attention to in Science due to a lovely girl called Lorraine sat on the next desk being quite the distraction  

I had a widebeam pull out in front of me in Milton Keynes, and he set off EXTREMELY slowly. After following him for what seemed like an eternity, I pulled up close to his stern for a while, to indicate that I'd like to pass. He refused to acknowledge I was there. Not wishing to give him a blast on the horn, I waited for a straight section and ran up to the bow to ask "would you mind letting me past please?" Not too easy , single handed on a 70ft boat, but, as I said, we were going extremely slowly. He begrudgingly pulled over at a suitable spot and gave me a load of abuse as I passed. I never have figured out why, and it still rankles.

[nicknorman]

2 minutes ago, monkeyhanger said:

... He begrudgingly pulled over at a suitable spot and gave me a load of abuse as I passed. I never have figured out why, and it still rankles.

Why? Because he was getting a kick out of controlling you, and then you went and spoilt it.

[Mike Todd]

1 hour ago, Keeping Up said:

When I planned my setup, I started from the fact that on open water I wanted to reach 7mph at the engine's maximum revs, ie 400 rpm per mph; so on open water at 800 rpm tickover I am doing 2mph. On a canal I found that the ratio increases to 450 rpm per mph, so at tickover I am doing about 1.75 mph (how do you type three-quarters).

 

This is using a 3:1 gearbox to an 18x14 prop. The slower turning by using 3:1 gives better ability to deal with any rubbish on the blades (the rubbish is moving slower through the water, and there's more torque to push it too).

 

Where appropriate I often lift the throttle slightly to pass moored boats at nearer 2mph, but if moorers hear of it they will usually shout at me to slow down.

We are similar: Beta 43 and 800rpm tickover. We have a Tyler Wilson hull which does seem to justify its claim to have lower resistance to forward motion and so our speed over the ground can be higher, rev for rev, than many other NBs. Nevertheless, at tickover we generally do max 2mph (checked via several different means, mostly GPS (which is not very accurate at such speeds!) on deepish water (canals don't generally offer open water conditions!) This still led to two or three occasions this year (unlike previous years) of being shouted at to slow down. Firstly it did seem that some folk, seemingly not used to moving much themselves, just get a kick out of shouting. Secondly, their boat rarely moved if effectively moored - those that did move about were on very slack lines anyway. 99+% of passing other boats was uneventful. Raw speed is not an accurate judge of how much it will affect a moored boat which is largely dependent on how it displaces the water whilst moving forward.

 

We also had a couple of experiences of following a slow boat and it can be irritating but not, in the long term, as much of a delay as it feels at the time. More concerned about the wear and tear on the gearbox. At the same time, there are many canals, especially narrow ones, where there are few places where allowing a boat to overtake is entirely safe, especially this year when vegetation management has been not as possible as normal. In any case, the contours will never go away! Whilst it may appear that there is plenty of width, straying much off line can be unfortunate. For example, just south of Cropredy where there is a long line of moored boats, an on coming boat gave the moored boats a very wide space and, even though we steered pretty close to them, we still hit a shallow obstruction which took us a while to free ourselves from, and we are not deep drafted by any standard.

 

All of which seems to support the view that there are few hard and fast rules when cruising and every situation has to be considered on its circumstance. The boat ahead may actually be in a better position to judge than you are with regard to overtaking. I would never want a boat to give way, only to end up stuck solidly on the shallow edge, or to cause an on coming boat to have to do an emergency stop to accommodate us, which would probably end up with three boats or more entangling themselves!

[IanD]

1 hour ago, nicknorman said:

Why? Because he was getting a kick out of controlling you, and then you went and spoilt it.

I had a very similar experience (me on a hire boat, him and SOH on a *very* shiny private boat) on the Trent & Mersey this year -- crawling along studiously ignoring me, refusing to let me get past (plenty of spaces) when asked (I had to get somewhere for dinner, last night before boat return), turning round and shouting "It's not a race!" when I got close passing moored boats (even tickover was too fast, kept having to drop out of gear) -- then after a couple of hours he stopped to wind in a marina to go back home, made me wait until he'd completely turned round (when he could have signalled me past while off the main line), then gave me a mouthful of abuse and challenged me to "sort it out" with him on the towpath when I pointed out that what he'd been doing wasn't good boating etiquette, and that the previous day I'd pulled over to let a boat past who obviously had to get somewhere faster than I did and had been catching me up.

 

His view was basically that he was out for a gentle pootle and wasn't in a hurry and everyone else should damn well do the same whether they liked it or not, because he was right and they were wrong, and he certainly wasn't going to be told otherwise by some oik on a hire boat, and would I like my face smashing in to prove it.

 

Muppet.

Edited October 13, 2020 by IanD

[mrsmelly]

11 hours ago, Wanderer Vagabond said:

The set up of your boat does seem to offer an explanation of how to get such slow speeds. My normal cruising rpm according to the tach is 1600 rpm which will give me between 2.9 and 3.4 mph dependent on the depth of water. If you were running at 900 - 1000 rpm (given that 2000rpm seems to give you 2.8 mph) then I would guess that your speed would be well below 2mph, such as our boat today, whereas 900rpm on mine gives me about 1.9 - 2mph.

 

As I said in my OP I'm in no rush and if I find myself travelling at tick-over whether behind a slow boat,or past moored boats, so be it, it is just that when speed goes below tickover it starts to become a PITA rather than a pleasure. Constantly kicking from drive into neutral and back again can't be doing the drive plates much good.

 

I would have to say that if I were in the position of travelling that slow, either through choice or engine defect, I would certainly be looking to wave anyone going faster than me past so there is a slight element of irritation when others don't do the same, but then if someone is travelling at a speed at which I can just run the engine at a constant speed I'll be content just to remain behind them. 

 

 

You must have asmall prop?? My 18 x 12 has us running at 1000 to 1100 revs at normal cruising speed and 1600 would be river mode. Nowt wrong with more revs though as it will charge yer batteries and work the engine a little more. The downside is that some numpties will shout slow down just because the engine is spinning faster.

[peterboat]

16 hours ago, mrsmelly said:

Not much pitch on the prop and or small prop. Some hire fleets deliberately fit smaller props to mean they run faster to ensure battery charging as thats the usual call out problem of flat batteries and its to try and negate that. Some gearboxes are 2 to one and some 3 etc etc.

My old ex share/hire boat had a 16 inch prop on it way to small when I dry docked it for the first time the owner part exchanged it for something more suitable, it saved fuel, noise and helped me on the trent as my engine wasnt screaming with me going nowhere