HDPE canal boat

[shaun15124]

2 minutes ago, IanD said:

 

The posts you showed earlier (and on your website) had a big internal steel frame, so not "entirely from HDPE"... 😉 

 

Have you now got rid of this -- and if so what have you replaced it with to get a stiff enough hull for canal use?

 

I'm genuinely interested, making this work entirely from HDPE is a significant challenge given the material properties... 🙂 

 

If these can be solved (along with other issues like expansion, which proved to be a major problem (leaks!!!) with the steel-hulled boats built in the last century with fibreglass tops) then HDPE does have advantages over a steel hull, as you point out. It may take several years of having such boats bashed around the canal system without problems to convince some of the novelty-resistant diehards on CWDF, though... 😉 

 

(certainly not me, I'm a fan of using new technology so long as it works and is better than what is used today)

Thank you for your interest, and I appreciate the thoughtful questions! You're absolutely right that our earlier posts and designs did feature an internal steel frame, and that was indeed part of our prototype build.

 

This steel framing helped us test various aspects of the boat’s durability and performance under real-world conditions while we worked to understand how to optimize the use of HDPE for the hull and structure.

 

Since then, we’ve made significant progress in refining our design and have transitioned away from the steel frame entirely. The steel was a critical part of our early learning phase, but as we’ve gained more insights, we’ve moved toward a more innovative approach using HDPE throughout the boat’s structure. This transition has been informed by our own experiences and expert advice, particularly regarding the need to address issues like thermal expansion and flexibility that arise when combining steel and HDPE.

 

To maintain a stiff, durable hull without steel, we've developed a new design that utilizes HDPE in a more integrated and structurally efficient way. The hull is built using a HDPE framework, which accounts for the material’s natural flexibility while providing the necessary rigidity for canal use. We've also incorporated careful design features to ensure that the hull can withstand the stresses of the waterway, such as reinforced ribs and strategic strengthening in key areas. This design allows for the natural expansion and contraction of HDPE without the risk of leaks or structural failure, something that was a challenge in earlier designs using steel.

 

You're also right that HDPE has some clear advantages over steel when it comes to corrosion resistance, weight, and ease of maintenance. However, as you've pointed out, the material's flexibility does pose challenges in ensuring the boat remains stiff and resilient over time. That’s why we've focused so heavily on engineering a solution that balances these factors, ensuring that the boat remains strong, stable, and capable of withstanding the demanding conditions of the canal system.

 

We understand that innovation can take time to be fully accepted, especially when it challenges traditional materials and methods. However, we believe that the new HDPE design offers significant benefits, and we’re excited to see how it holds up over time. Our goal is to create a sustainable, long-lasting solution that’s well-suited to narrowboating, and we’re confident that this approach will prove itself with continued testing and refinement.

 

Thanks again for your interest, and we’re excited to see where this journey takes us. If you have any further questions or thoughts, don’t hesitate to reach out!

[IanD]

1 minute ago, shaun15124 said:

Thank you for your interest, and I appreciate the thoughtful questions! You're absolutely right that our earlier posts and designs did feature an internal steel frame, and that was indeed part of our prototype build.

 

This steel framing helped us test various aspects of the boat’s durability and performance under real-world conditions while we worked to understand how to optimize the use of HDPE for the hull and structure.

 

Since then, we’ve made significant progress in refining our design and have transitioned away from the steel frame entirely. The steel was a critical part of our early learning phase, but as we’ve gained more insights, we’ve moved toward a more innovative approach using HDPE throughout the boat’s structure. This transition has been informed by our own experiences and expert advice, particularly regarding the need to address issues like thermal expansion and flexibility that arise when combining steel and HDPE.

 

To maintain a stiff, durable hull without steel, we've developed a new design that utilizes HDPE in a more integrated and structurally efficient way. The hull is built using a HDPE framework, which accounts for the material’s natural flexibility while providing the necessary rigidity for canal use. We've also incorporated careful design features to ensure that the hull can withstand the stresses of the waterway, such as reinforced ribs and strategic strengthening in key areas. This design allows for the natural expansion and contraction of HDPE without the risk of leaks or structural failure, something that was a challenge in earlier designs using steel.

 

You're also right that HDPE has some clear advantages over steel when it comes to corrosion resistance, weight, and ease of maintenance. However, as you've pointed out, the material's flexibility does pose challenges in ensuring the boat remains stiff and resilient over time. That’s why we've focused so heavily on engineering a solution that balances these factors, ensuring that the boat remains strong, stable, and capable of withstanding the demanding conditions of the canal system.

 

We understand that innovation can take time to be fully accepted, especially when it challenges traditional materials and methods. However, we believe that the new HDPE design offers significant benefits, and we’re excited to see how it holds up over time. Our goal is to create a sustainable, long-lasting solution that’s well-suited to narrowboating, and we’re confident that this approach will prove itself with continued testing and refinement.

 

Thanks again for your interest, and we’re excited to see where this journey takes us. If you have any further questions or thoughts, don’t hesitate to reach out!

 

Thanks for the honest reply 🙂 

 

I do have the same question as for Bug Boats -- to get enough stiffness (especially torsional) it sounds like you need an overall hull structure (including HDPE bracing -- and insulation?) which is considerably thicker than a conventional steel hull with insulation in between the stringers. This wouldn't be a problem on a wider boat, but on a narrowboat every inch of internal width is vital giving the difficulties of fitting the internals in. IIRC my boat is 185cm/6'1" inside after lining and fitting out -- how about yours?

[Joesy]

1 hour ago, shaun15124 said:

 

Thank you so much for your interest and for appreciating the novelty of our concept! We’re incredibly proud to be the first company in the world to manufacture A canal boat entirely from HDPE.

 

This pioneering journey has involved comprehensive research and development. We are now in the production phase of the project we are building for Crick, which I believe I have previously mentioned. It will be situated at the Albert Docks in Liverpool before proceeding to Crick.

 

I can confirm that we have no connection whatsoever with the question mentioned. Please check out our website at www.formationplastics.co.uk

for all the information that we currently provide.

 

Thank you for the clarification.

 

Your boat is lovely and I will continue to watch your project with interest.

 

Would a hdpe narrow boat be able to carry the same weight as a steel boat?

I have a tentative plan that includes a boat and a piano.

 

Thank you for your time

[Alan de Enfield]

19 minutes ago, Joesy said:

I have a tentative plan that includes a boat and a piano.

 

 

 

[shaun15124]

I truly believe that integrity is key in this process, and we are still learning as we go. Our approach has been shaped by real-world experience and expert input, and we continue to refine our design to meet the challenges of building a narrowboat entirely from HDPE.

 

To address your concern about hull stiffness and torsional strength, you're absolutely right that we needed to create a structure that’s stronger than traditional steel hulls, particularly when working with a material like HDPE. We've designed the hull with a HDPE framework, which allows us to achieve the necessary strength while maintaining flexibility where needed. The structure is thicker than conventional steel hulls in certain areas, especially around key structural points, to ensure stability and resilience on the canal. However, this does impact internal space slightly, and we’re mindful of how every inch counts in a narrowboat, especially with the need for practical living space.

 

In terms of your own boat’s internal width of 185cm (6'1"),

 

our narrowboat design has an internal width of 1700mm and a height of 2000mm this is before fit out . We understand that maximizing internal space is crucial for fitting out and creating a comfortable living environment. We’ve been very careful to balance the need for a strong, durable hull with the need for usable space inside. While some space will inevitably be lost due to the thickness of the hull, we are committed to ensuring that the final design is as efficient as possible, without compromising too much on internal room.

We’re constantly refining our approach, and your insights are incredibly helpful

25 minutes ago, Joesy said:

Thank you for the clarification.

 

Your boat is lovely and I will continue to watch your project with interest.

 

Would a hdpe narrow boat be able to carry the same weight as a steel boat?

I have a tentative plan that includes a boat and a piano.

 

Thank you for your time

Thank you so much for your kind words and for following our project—it really means a lot!

 

To answer your question, an HDPE narrowboat is designed to have a similar carrying capacity to a steel boat, but the specifics depend on the hull design and ballast configuration. HDPE itself is much lighter than steel, which means we have to carefully balance the boat using ballast (typically concrete or other dense materials) to achieve the right draft and stability. This ensures the boat sits properly in the water and can safely carry additional weight.

 

Regarding your plan for a boat and a piano—what a wonderful idea! An HDPE narrowboat can absolutely support a piano, but it’s essential to consider the piano’s weight and how it might be distributed. As with any boat, careful planning around weight distribution is key to maintaining stability and performance. With HDPE’s inherent buoyancy and the way we design our boats, there’s flexibility to customize the ballast and layout to suit specific needs like yours.

If you’d like, we’d be happy to discuss further to ensure your dream of having a piano on board becomes a reality. Let me know if you have any other questions—I’d love to help!

[Joesy]

Thank you.

It is all very much in a tentative stage right now.

But if it ever comes to fruition I will be considering all options. And a rust free boat would be high on the list of wonderful things

[Alan de Enfield]

27 minutes ago, shaun15124 said:

In terms of your own boat’s internal width of 185cm (6'1"),

 

our narrowboat design has an internal width of 1700mm and a height of 2000mm this is before fit out

 

With a conventional steel NB with an internal width of 6' 1" it is possible to have a cross bed thus making a more efficient use of the 'length', something very important in boats, particularly under (say) 45 foot.

 

With your boat at just under 5' 7" width, this means that only the friends of Snow White can have 'cross beds', and with the result that the bed will need to be lengthways, losing valuable 'length'.

Edited November 20, 2024 by Alan de Enfield

[shaun15124]

[Alan de Enfield]

Is the 2000mm dimension ceiling to floor, or ceiling to 'the inside surface of the base 'plate' ?

Is there a space for ballast  and a floor to be incorporated/included into the 2000mm ?

Edited November 20, 2024 by Alan de Enfield

[IanD]

9 minutes ago, Alan de Enfield said:

 

With a conventional steel NB with an internal width of 6' 1" it is possible to have a cross bed thus making a more efficient use of the 'length', something very important in boats, particularly under (say) 45 foot.

 

With your boat at just under 5' 7" width, this means that only the friends of Snow White can have 'cross beds', and with the result that the bed will need to be lengthways, losing valuable 'length'.

 

I don't think the cross bed is the biggest issue, anyway many people (including me) find these are too short even in a conventional boat -- it's other places like trying to get a lengthwise bed in with a usable walkway down the side, or units each side of a kitchen with a wide enough walkway to open cabinet doors, or get a dinette with a usable walkway past it, or a decent-sized shower and a door or sink/toilet/door in the bathroom. Six inches doesn't sound like much, but it's going to make a big difference in all these cases.

[shaun15124]

Thank you for the question! The 2000mm internal height is measured from ceiling to floor,

[IanD]

1 hour ago, shaun15124 said:

I truly believe that integrity is key in this process, and we are still learning as we go. Our approach has been shaped by real-world experience and expert input, and we continue to refine our design to meet the challenges of building a narrowboat entirely from HDPE.

 

To address your concern about hull stiffness and torsional strength, you're absolutely right that we needed to create a structure that’s stronger than traditional steel hulls, particularly when working with a material like HDPE. We've designed the hull with a HDPE framework, which allows us to achieve the necessary strength while maintaining flexibility where needed. The structure is thicker than conventional steel hulls in certain areas, especially around key structural points, to ensure stability and resilience on the canal. However, this does impact internal space slightly, and we’re mindful of how every inch counts in a narrowboat, especially with the need for practical living space.

 

In terms of your own boat’s internal width of 185cm (6'1"),

 

our narrowboat design has an internal width of 1700mm and a height of 2000mm this is before fit out . We understand that maximizing internal space is crucial for fitting out and creating a comfortable living environment. We’ve been very careful to balance the need for a strong, durable hull with the need for usable space inside. While some space will inevitably be lost due to the thickness of the hull, we are committed to ensuring that the final design is as efficient as possible, without compromising too much on internal room.

We’re constantly refining our approach, and your insights are incredibly helpful

Thank you so much for your kind words and for following our project—it really means a lot!

 

To answer your question, an HDPE narrowboat is designed to have a similar carrying capacity to a steel boat, but the specifics depend on the hull design and ballast configuration. HDPE itself is much lighter than steel, which means we have to carefully balance the boat using ballast (typically concrete or other dense materials) to achieve the right draft and stability. This ensures the boat sits properly in the water and can safely carry additional weight.

 

Regarding your plan for a boat and a piano—what a wonderful idea! An HDPE narrowboat can absolutely support a piano, but it’s essential to consider the piano’s weight and how it might be distributed. As with any boat, careful planning around weight distribution is key to maintaining stability and performance. With HDPE’s inherent buoyancy and the way we design our boats, there’s flexibility to customize the ballast and layout to suit specific needs like yours.

If you’d like, we’d be happy to discuss further to ensure your dream of having a piano on board becomes a reality. Let me know if you have any other questions—I’d love to help!

 

What do you mean by "1700mm before fitout" -- will this shrink further by the time things like insulation/wooden lining is added (and don't forget cables/pipes/ducts!), or is this finished wood-wall-to-wood-wall (which is what my 185cm was)?

Edited November 20, 2024 by IanD

[nb Innisfree]

5'7" before ballast etc, so useless for me at 6'

 

 

I always fancied a nb in marine aluminium. 

[shaun15124]

The insulation is already built into the wall, and we've provided the measurements to the boatfitter. The picture above was a 2D image; I will update with more pictures later to show that our boatfitter was satisfied with everything, including the sizes.

 

Regarding the pipework, it will be integrated within the green parts.

the internal size is 6ft 6 with ballast 

[Alan de Enfield]

1 minute ago, shaun15124 said:

Regarding the pipework, it will be integrated within the green parts

 

 

Will you have easy access to the pipes and wiring for upgrades, repairs, viewing etc. Rememeber that the BSS examiner needs to see the complete run of gas pipe - 'hidden' in the walls is an examination fail.

[IanD]

2 minutes ago, Alan de Enfield said:

 

 

Will you have easy access to the pipes and wiring for upgrades, repairs, viewing etc. Rememeber that the BSS examiner needs to see the complete run of gas pipe - 'hidden' in the walls is an examination fail.

If you have gas pipes... 😉 

[shaun15124]

This is an excellent question. Our boatfitters, who have over 20 years of experience in the boat industry, including one from Aintree Boats, are addressing this closely with the customer.

[nb Innisfree]

12 minutes ago, nb Innisfree said:

5'7" before ballast etc, so useless for me at 6'

 

 

I always fancied a nb in marine aluminium. 

My mistake, 6' 6" height would be good

Edited November 20, 2024 by nb Innisfree

[IanD]

6 minutes ago, shaun15124 said:

The insulation is already built into the wall, and we've provided the measurements to the boatfitter. The picture above was a 2D image; I will update with more pictures later to show that our boatfitter was satisfied with everything, including the sizes.

 

Regarding the pipework, it will be integrated within the green parts.

the internal size is 6ft 6 with ballast 

So is the wooden lining included on that drawing, or does it (and any cables?) have to go inside the 1700mm?

 

Even if it doesn't, an interior 15cm/6" narrower than a conventional steel hull is definitely going to mean some difficult compromises with the fitout... 😞 

[shaun15124]

As far as I am aware, it has included the lining on it.

[IanD]

10 minutes ago, shaun15124 said:

As far as I am aware, it has included the lining on it.

From what you've described, it does look like you've addressed the structural issues with HDPE, and those resulting from trying to make a hybrid HDPE/steel structure -- which were pointed out in earlier discussions, and you have found were an issue in practice, so engineering theory and real life agree 🙂 

 

I can certainly see the advantages of HDPE, apart from all the recycling/sourcing issues the only significant disadvantage seems to be the reduced internal width, which is definitely going to compromise internal layout in a narrowboat -- it would be no problem in a wideboat.

 

Rather than ballasting the boat to a conventional draft (around 2' at the stern) you might also want to look into the possibility of using the light weight of HDPE to allow a reduced draft, though stability might become a problem even with dense ballast low down (steel is better than concrete for this, but much more expensive). Some quick estimates suggest that this could easily halve the propulsion power needed in typical narrow/shallow UK canals, which would make a big difference to electric/hybrid boats in particular, especially for cruising outside the summer months (double the range or half the solar needed). It would also be trivial to use 2 smaller props with electric drive to allow shallower draft, each one would only need about a quarter the power of the single prop in a conventional draft boat. You'd probably need a bow thruster to cope with cross-winds, but again less power needed for this than a deeper draft hull.

[nb Innisfree]

But then reduced draft would mean reduced air draft as o/a boat height allows clearance between canal bed and bridge arch. 

[IanD]

29 minutes ago, nb Innisfree said:

But then reduced draft would mean reduced air draft as o/a boat height allows clearance between canal bed and bridge arch. 

Yes it would, but this is rarely a problem unless you pile loads of stuff on the roof -- most conventional draft boats with a foot or more "on top" have no very few problems with air draft.

 

You really would have to bend down pretty low in tunnels hike Harecastle or Standedge though -- however I'd have thought that having half the power use 99.99% of the time more than justified having problems like this 0.01% of the time... 😉 

Edited November 20, 2024 by IanD
no problems ==> very few

[Tony Brooks]

1 minute ago, IanD said:

Yes it would, but this is rarely a problem unless you pile loads of stuff on the roof -- most conventional draft boats with a foot or so "on top" have no problem with air draft.

 

I am not sure about that. I had to take a sort radio aerial off for a bridge on the South Stratford, a Rail Bridge on the Wey, two bridges on the Basingstoke and one had only about 12mm clearance (I know few do the Basingstoke). I would not pass the tunnel to the basin on the end of the Caldon, and I am sure we came across a few other bridges where it was prudent to take the radio aerial off. I doubt we would have got under the Wey bridge if it had a bit of fresh flowing. Noting on roof apart from horizontal solar panels towards the back and flying saucer vents.

[IanD]

13 minutes ago, Tony Brooks said:

 

I am not sure about that. I had to take a sort radio aerial off for a bridge on the South Stratford, a Rail Bridge on the Wey, two bridges on the Basingstoke and one had only about 12mm clearance (I know few do the Basingstoke). I would not pass the tunnel to the basin on the end of the Caldon, and I am sure we came across a few other bridges where it was prudent to take the radio aerial off. I doubt we would have got under the Wey bridge if it had a bit of fresh flowing. Noting on roof apart from horizontal solar panels towards the back and flying saucer vents.

OK, corrected to "very few" problems. Maybe that changes the tradeoff to half the power/double the range 99.9% of the time and air draft/crouching 0.1% of the time. I still know which I'd choose... 😉