Rubbish to stop or go into Reverse

[robtheplod]

Hi All

Since getting Lily in 2019 she's been a fab boat, but I noticed that when moving forward and wish to stop/go into reverse she's not keen!  When we have the dance at bridges when someone else is coming through I can sit there in reverse for a fair while before she will actually go backwards and i jus have to smile nicely while people wonder if im going to do anything!.... I'm sure I've not noticed this on other boats i've been on. Always thought its just one of those things, but thought i'd ask the question at least. I dont have much info other than the prop is 18" - some rubbishy pics below.... 

 

This is especially bad in locks where i can have her in full reverse but still she moves forward - i know this occurs in the 'rush', but just checking if i can improve it?

 

 

 

Edited October 25, 2023 by robtheplod

[Tracy D'arth]

Normal, its a boat! Not a BMW. Anticipation is required.

[Laurie Booth]

1 minute ago, Tracy D'arth said:

Normal, its a boat! Not a BMW. Anticipation is required.

Ditto

[IanM]

They all do that*, sir 😁

 

 

 

 

 

 

 

 

 

*Before someone jumps in and becomes all high and mighty that theirs doesn't, obviously some boats are better than others.

[robtheplod]

reassuring thanks guys!

[Graham and Jo]

Is it just that all boats do that or is there genuine problem with reverse. Dotterel had a problem with its reverse gear that initially manifested as slow to go in reverse and finally a oh my god we are going to die problem. 

 

So when you engage reverse does the boat immediately start throwing water forward down both sides?

 

Cheers Graham 

[Higgs]

Just now, Graham and Jo said:

Is it just that all boats do that or is there genuine problem with reverse. Dotterel had a problem with its reverse gear that initially manifested as slow to go in reverse and finally a oh my god we are going to die problem. 

 

So when you engage reverse does the boat immediately start throwing water forward down both sides?

 

Cheers Graham 

 

It should do, but it's overcoming the inertia that takes time.

 

 

[nicknorman]

There are certainly differences in “reverse power” depending on the type of prop. Our current boat is pretty good at stopping quickly, the one we used to borrow, much less so. Deep draft and hence large diameter prop maybe helps, but if it bugs you you could invest in a decent prop like a Crowther.

[Tonka]

Have you checked that when you go into reverse that the prop is turning in reverse. I.e that the linkage is actually selecting reverse fully

1 minute ago, nicknorman said:

There are certainly differences in “reverse power” depending on the type of prop. Our current boat is pretty good at stopping quickly, the one we used to borrow, much less so. Deep draft and hence large diameter prop maybe helps, but if it bugs you you could invest in a decent prop like a Crowther.

Crowther are no more

[nicknorman]

1 minute ago, Tonka said:

 

Crowther are no more

Oh dear, didn’t know that. Who makes decent props these days?

[Bee]

When you engage reverse does the shaft actually rotate? If it only slowly rotates then gradually picks up speed then its a gearbox problem. If it takes a little while for the boat to respond when spinning normally then they do indeed all do that, its asking a lot for a prop to actually grab enough water to stop 10 tons or more of boat

[magnetman]

3 minutes ago, nicknorman said:

Oh dear, didn’t know that. Who makes decent props these days?

Axiom ? 

 

12 minutes ago, Graham and Jo said:

. Dotterel had a problem with its reverse gear that initially manifested as slow to go in reverse and finally a oh my god we are going to die problem. 

 

...

 

Cheers Graham 

 

Did you manage to adequately resolve this issue?

[Rob-M]

When stationary what happens when you go in to reverse, does it still take time to respond or does it start moving straight away?

[Stroudwater1]

4 minutes ago, nicknorman said:

There are certainly differences in “reverse power” depending on the type of prop. Our current boat is pretty good at stopping quickly, the one we used to borrow, much less so. Deep draft and hence large diameter prop maybe helps, but if it bugs you you could invest in a decent prop like a Crowther.

Sadly we have a deep draft large prop but are extremely rubbish at reversing. I’m sure it is inertia in large part but the prop must have a part as water shoots out in full foreward but dribbles pitifully past in reverse. Maybe that’s down to the swim shape? 
 

We just have to try and adapt. Most hire boats we used stop far faster, within half a length, we stop in just over 1 1/2 lengths 🙄

 

At least with a traditional engine there’s heaps of smoke indicating that something is happening 

[magnetman]

3 minutes ago, Rob-M said:

When stationary what happens when you go in to reverse, does it still take time to respond or does it start moving straight away?

I've had 6 narrow boats and only one of them moved instantly when gear engaged. It had a big engine (Petter PJ4) and a big prop (23*20).

 

The others didn't have the 'stern dip' in forward gear although the barge did but again that had a very torquey engine and correct prop. 

 

 

Edited October 25, 2023 by magnetman

[blackrose]

35 minutes ago, IanM said:

*Before someone jumps in and becomes all high and mighty that theirs doesn't, obviously some boats are better than others.

 

I'm not being all high and mighty but mine doesn't! It obviously depends of how fast I'm moving forwards to start with, but when I go into reverse my boat stops fairly quickly and then moves backwards. That's stopping a 29 tonne boat with a 55hp engine swinging a 18.5" X 13" prop through a 2:1.09 reduction ratio gearbox.

 

The OP said he can be in "full reverse" in a lock and his boat is still moving forwards. Then a couple of people chimed in saying all boats do that... Really? In full reverse? That's not normal surely?

Edited October 25, 2023 by blackrose

[magnetman]

It depends how fast the forward movement is. 

 

Some boats will stop quicker than others.

 

The best thing is to go into locks slowly and not need reverse to stop but use a rope.

[Tonka]

15 minutes ago, magnetman said:

Axiom ? 

 

 

Did you manage to adequately resolve this issue?

Axiom are no more too.

If you do a search on the forum somebody will have found who the good prop makers are

[magnetman]

https://clementsengineering.co.uk

 

 

 

No connection I just found them on a g search using the term crowthers propeller. 

 

 

This looks quite serious. 

 

[robtheplod]

Thanks all. It all engages fine and i see the wash up the side etc... its definately 'different' to our other shareboat in how responsive stop/reverse is.

 

 as an aside when generally cruising i seem to need more revs than others i see - seems to be around 1700rpm for slow walking pace... could this be related?

[Tracy D'arth]

3 minutes ago, robtheplod said:

Thanks all. It all engages fine and i see the wash up the side etc... its definately 'different' to our other shareboat in how responsive stop/reverse is.

 

 as an aside when generally cruising i seem to need more revs than others i see - seems to be around 1700rpm for slow walking pace... could this be related?

Certainly, what is the boat length, weight, maker etc. and engine and prop?

[robtheplod]

3 minutes ago, Tracy D'arth said:

Certainly, what is the boat length, weight, maker etc. and engine and prop?

I'll try!

 

This is the info in the documentation. Its PRM150

 

[blackrose]

26 minutes ago, magnetman said:

 

The best thing is to go into locks slowly and not need reverse to stop but use a rope.

 

I always go into locks very slowly but I prefer stopping the boat with the engine before any ropes are deployed. I've seen bollards ripped out of the ground by people who like stopping their boats with ropes.  Also it depends whether one is going uphill or downhill. Going uphill single handed into a deep lock it's not always easy to get a rope around a bollard.

Edited October 25, 2023 by blackrose

[magnetman]

Some boats are deliberately underpropped to get more charging from the alternator and discourage excessive speeding. 

 

Just now, blackrose said:

 

I always go into locks very slowly but I prefer stopping the boat with the engine before any ropes are deployed. I've seen bollards ripped out of the ground by people who like stopping their boats with ropes.  Also it depends whether one is going uphill or downhill. Going uphill single handed into a deep lock it's not easy to get a rope around a bollard.

Depends on the lock. If it is possible to get orf just below the lock with the bow rope I will do that. Not always an option but very often is. 

 

 

[robtheplod]

1 minute ago, magnetman said:

Some boats are deliberately underpropped to get more charging from the alternator and discourage excessive speeding. 

 

it used to have a generator on it i think so maybe thats why?