Enclosed bow

[Willonaboat]

On 15/12/2023 at 00:09, IanD said:

Given that my BT runs off the main 48V battery that pushes the boat along, if there's no power for the BT this would be the least of my worries... 😉

 

This is why I chose to have two separate batteries for the (24v) bow thruster rather than have a 48v bowthruster powered from the main 48v battery bank. It gives a level of redundancy and takes the pressure off the main 48v propulsion battery bank in the event of them being at a low SoC. Perhaps unlikely to happen with a large solar array and backup generator but I was playing a game of What If..? and decided this was the way I'd go. But as always there are many ways of doing things and most of them are not straightforward right/wrong ways.

 

[IanD]

8 minutes ago, Willonaboat said:

 

This is why I chose to have two separate batteries for the (24v) bow thruster rather than have a 48v bowthruster powered from the main 48v battery bank. It gives a level of redundancy and takes the pressure off the main 48v propulsion battery bank in the event of them being at a low SoC. Perhaps unlikely to happen with a large solar array and backup generator but I was playing a game of What If..? and decided this was the way I'd go. But as always there are many ways of doing things and most of them are not straightforward right/wrong ways.

 

A bowthruster uses a negligible amount of energy because it's only on for a short time. IIRC mine's about 5kW flat out (it's variable speed and I rarely use full power), even running it for a minute uses less than 0.1kWh.

 

When I looked at the costs it was cheaper to run 48V cables along the boat (only 25mm2 IIRC) than to add separate batteries for the 48V BT, and have to worry about keeping them charged and lifetime. Not really feasible with 24V though, you'd need 100mm2 cables, and definitely a no-no for 12V which would need 400mm2... 😉

Edited December 18, 2023 by IanD

[Jon57]

17 hours ago, cuthound said:

This is how mine has the lip on the inside of the handrail.

 

It also allows the fenders to be moved wherever they are needed by the use of metal clips which hook onto the inner lip.

This also help when your not watching your hand grip. 

[Guest]

1 minute ago, Jon57 said:

This also help when your not watching your hand grip. 

 

Once caught my finger in one of those and boy did it hurt.

[cuthound]

5 minutes ago, Jon57 said:

This also help when your not watching your hand grip. 

 

Mine has drainage holes in the upstand. Here is a close up of the rear most drainage hole.

[Willonaboat]

26 minutes ago, IanD said:

A bowthruster uses a negligible amount of energy because it's only on for a short time. IIRC mine's about 5kW flat out (it's variable speed and I rarely use full power), even running it for a minute uses less than 0.1kWh.

 

When I looked at the costs it was cheaper to run 48V cables along the boat (only 25mm2 IIRC) than to add separate batteries for the 48V BT, and have to worry about keeping them charged and lifetime. Not really feasible with 24V though, you'd need 100mm2 cables, and definitely a no-no for 12V which would need 400mm2... 😉

 

Correct. Mine is variable speed too.

 

I chose a 24v bowthruster because of the (percieved) benefit of redundancy and 2 x 12v batteries in the bowlocker adds 60kg useful weight in the bow. The battery cables are short as the BT and batteries are next to each other so 75mm2 cable more than does the job. For me the cost was secondary to the benefit of redundancy (and useful weight in the bow). I don't worry about keeping the batteries charged - who does with an appropriate charger/system installed?

[IanD]

1 minute ago, Willonaboat said:

 

Correct. Mine is variable speed too.

 

I chose a 24v bowthruster because of the (percieved) benefit of redundancy and 2 x 12v batteries in the bowlocker adds 60kg useful weight in the bow. The battery cables are short as the BT and batteries are next to each other so 75mm2 cable more than does the job. For me the cost was secondary to the benefit of redundancy (and useful weight in the bow). I don't worry about keeping the batteries charged - who does with an appropriate charger/system installed?

Yeah, charging isn't a problem in reality. With the benefit of hindsight, having batteries in the bow locker would have saved some steel ballast... 😉

[Willonaboat]

9 minutes ago, IanD said:

Yeah, charging isn't a problem in reality. With the benefit of hindsight, having batteries in the bow locker would have saved some steel ballast... 😉

 

With the benefit of hindsight I'd have had a fully enclosed bow rather than the reduced length welldeck of 2' that we have (giving a slightly longer cabin). It's there if needed for docking, etc, although so far not really needed, but it's too small for anything other than a brief perch. And so far we've spent more time clearing it of leaves and dirt than using it. I feel some steelwork coming on in a year or two...

 

Edited December 18, 2023 by Willonaboat

[Jon57]

10 minutes ago, cuthound said:

 

Mine has drainage holes in the upstand. Here is a close up of the rear most drainage hole.

Mouse holes are ok if kept clean of leaves and the trim doesn’t change much. Also if in the right place. I Have similar on the front deck . Would have been better just leaving a gap. No problems with them getting blocked unlike the mouse holes, hence the rodding brush. Ok if on board all the time but can be a problem if not.

[magnetman]

Yes I think the mousehole (butt weld elbow or is it a straight tube) should be larger diameter. 

 

Maybe a rat hole ! Or even a cathole.

 

As long as people can't get bodily appendages caught there seems to be a 'big as possible' argument. 

I would also argue that it would be worth having that part in stainless. It would need tig welding but could be done and would be a nice item. 

Hull penetrations such as skin fittings or drains which involve tubes want to be done in stainless. 

 

 

(above water)

Edited December 18, 2023 by magnetman

[cuthound]

10 minutes ago, Jon57 said:

Mouse holes are ok if kept clean of leaves and the trim doesn’t change much. Also if in the right place. I Have similar on the front deck . Would have been better just leaving a gap. No problems with them getting blocked unlike the mouse holes, hence the rodding brush. Ok if on board all the time but can be a problem if not.

 

I've not had any issues in 10 years of ownership with the mouse holes even though the nearby trees drop a lot of leaves on my boat.

[Jon57]

37 minutes ago, Jon57 said:

This also help when your not watching your hand grip. 

Are you sure it wasn’t your ring.🤣

37 minutes ago, M_JG said:

 

Once caught my finger in one of those and boy did it hurt.

 

1 minute ago, Jon57 said:

Are you sure it wasn’t your ring.🤣

 

[magnetman]

I prefer a flat bridge over the top to a thin bar. 

[Jon57]

Just now, magnetman said:

I prefer a flat bridge over the top to a thin bar. 

Me too .

[blackrose]

52 minutes ago, magnetman said:

I prefer a flat bridge over the top to a thin bar. 

 

Yes. Liverpool Boats left 6" drainage gaps in my intergal handrails. Quite disconcerting as you're walking along the gunwale and grab thin air. I had flat bar welded over them. 

[Willonaboat]

22 minutes ago, blackrose said:

 

Yes. Liverpool Boats left 6" drainage gaps in my intergal handrails. Quite disconcerting as you're walking along the gunwale and grab thin air. I had flat bar welded over them. 

 

That's what we have - flat bar welded over the drainage channels. The flat bar is a continuation of the finger-grip handrails.

 

[blackrose]

3 hours ago, IanD said:

A bowthruster uses a negligible amount of energy because it's only on for a short time. IIRC mine's about 5kW flat out (it's variable speed and I rarely use full power), even running it for a minute uses less than 0.1kWh.

 

When I looked at the costs it was cheaper to run 48V cables along the boat (only 25mm2 IIRC) than to add separate batteries for the 48V BT, and have to worry about keeping them charged and lifetime. Not really feasible with 24V though, you'd need 100mm2 cables, and definitely a no-no for 12V which would need 400mm2... 😉

 

So you power your BT from batteries at the stern? It sounds odd to me with all the voltage drop, I guess that's not an issue with 48v so I'm sure you know what you're doing. I'm old school with a diesel engine and a 12v system. 

 

Keeping the BT batteries charged has never been an issue on my boat. Whatever source is charging the start battery soon sends its charge to the BT batteries via a VSR. I've never lost BT power over the last 18 years so I find it difficult to understand why charging the BT batteries seems to be such a common problem - or why it's perceived as such.

Edited December 18, 2023 by blackrose

[IanD]

13 minutes ago, blackrose said:

 

So you power your BT from batteries at the stern? It sounds odd to me with all the voltage drop, I guess that's not an issue with 48v so I'm sure you know what you're doing. I'm old school with a diesel engine and a 12v system. 

 

Keeping my BT batteries charged has never been an issue on my boat. Whatever source is charging the start battery soon sends its charge to the BT batteries via a VSR. I've never lost BT power over the last 18 years.

 

Yes, that's absolutely fine with a 48V system, 25mm2 is the cable size recommended by Vetus for up to 124' cable length (maximum BT power is 3.1kW).

 

I don't have an engine start battery as such, there's a small 12V one for the generator but that's in the stern along with the 48V batteries -- DC power for the rest of the boat (relatively low power stuff like lights, pumps etc.) is 24V from a DC-DC converter (and there's another small 12V DC-DC to charge the genny battery). So I'd have to run 48V to the bows anyway to run a battery charger there if the BT had its own batteries -- and in this case, I might as well have a 48V BT...

Edited December 18, 2023 by IanD

[ditchcrawler]

3 hours ago, Jon57 said:

Mouse holes are ok if kept clean of leaves and the trim doesn’t change much. Also if in the right place. I Have similar on the front deck . Would have been better just leaving a gap. No problems with them getting blocked unlike the mouse holes, hence the rodding brush. Ok if on board all the time but can be a problem if not.

 

I have the same and a pain.

[___]

On 18/12/2023 at 01:10, blackrose said:

 

I don't bowhaul in or out of locks. When you're single handed on a 29 tonne boat that's not really a practical option. 

They don’t make ‘em like they used to. I dare say my great grandmother could have taught you a trick or two.

[BoatinglifeupNorth]

3 hours ago, Captain Pegg said:

They don’t make ‘em like they used to. I dare say my great grandmother could have taught you a trick or two.

And her kids👶💪💪

[magnetman]

Bowhauling is easy if nobody is in a rush to get anywhere and one uses a suitably long piece of cotton rope.

 

I did find a good 4 strand nylon rope for this which is an excellent bondage rope as it is very similar to cotton.

 

Its called Rombul.. Nice and soft although it does harden with age.

 

Bowhauling is also quite satisfying. I'd not want to do it in pounds but around locks no worries. 

 

Heaviest I have hauled was 29 tonnes that was quite easy I imagine if it gets up to 40 tonnes it gets heavy and of course also depends on the draught.

 

 

[ditchcrawler]

How about this for an enclosed bow 

[IanD]

Wow... 😞

[magnetman]

Is it an undercover police surveillance unit or a livestock transport solution?

I'm sure I can see some sheep in there..