Why we have revisited the design of Canal Boats...

The current design of narrow boats in the UK canal system has not changed in decades. It derived from the powered working craft that entered use in the latter half of the 19th century with the introduction of steam propulsion to replace the use of horses.  This then progressed to the use of internal combustion engines (Bolinder)  and by the 1920’s most boats had been converted to run on these engines.  The hull forms are simplistic and as working boats most of the hull was dedicated to cargo with, as economic pressures grew on the operators, compact accommodation at the aft end of the vessel. This resulted in very diminutive fore and after deck spaces.

After the end of the second world war commercial traffic dwindled and was gradually replaced by the use of canals for leisure. By the 1960’s a hire industry was starting to become established. The boats built for this were standardised and mainly built from steel. To keep costs down very simple hull forms were (and still are) utilised. The layouts and aesthetic however mimicked the working craft with the established arrangement of small external spaces.  Three layouts evolved, the ‘trad’, ‘semi-trad’ and ‘cruiser’ arrangements. These configurations have now become part of the perceived family of ‘traditional’ boats.

When Floating Ohms’ design team started the design study for an all electric canal boat, we began, as is the norm for good engineering design, with a definition of the purpose and consequently the desired deliverables.

We deduced that a significant part of the purpose of taking to the canal system is to become immersed in the countryside and, when in towns and cities, to savour the character and history of that environment. These are predominantly outdoor activities. We also noted that a large number of the people involved in this form of leisure activity also have dogs - and love to walk them along towpaths and in the adjoining countryside. Outdoor activities.

The boat is, naturally, a form of mobile accommodation and so the interior should not be compromised in the design. Existing boats are, as we have alluded to previously, essentially all about the interior living spaces, and there are very many very good examples of this.

So the focus for our design team was the following:

• A design that maximises external leisure and entertainment spaces

• A design that does not impact the interior design or layout and should be capable of providing the equivalent interior volume as any similar sized traditional narrowboat.

• A design that has focus on the use of space and light that makes living aboard a pleasing and welcoming experience.

• A design that is efficient from a hydrodynamic perspective. This hull form should take into account the constraints of the canal system and avoid myopic design cul-de-sacs! In short the hull should look to maximise propulsive efficiency without tending towards extremes and, importantly deliver a boat that works for all the above requirements.

  
  

With these as a basis for taking a fresh look at the whole design, we looked at the boat design with a new, unbiased, view.  Firstly we examined the operating environment and its physical constraints, length, breadth, air draft and the fact that a proportion of the canal system is shallow. The constraints are well defined for each of the individual canal systems as listed by the Canal and River Trust Waterways dimensions document.  Consequently we used as the basis for the physical restrictions to be complied with and in order to access the whole system we find that the following maxima apply:

• an air draft of 1.7m (Coventry Canal)

• beam of 2.13m for narrow canals

•  and a maximum draft of 0.7m ( Aspley basin to Standedge Tunnel, Llangollen canal and Rubble Millennium canal)

• Maximum cruising speed 4 mph (3.47Knots)

  
  

The primary design constraints are driven by these factors.

As such we looked at maintaining the same volume of accommodation as equivalent existing designs. By looking carefully at the bow design we have been able to increase the volume and deck area at the bow whilst keeping the same distance from the forward accommodation bulkhead to the stem as would be normal for existing designs. However the advantage of developing the full, elliptical bow sections, which are a benefit to the hydrodynamics, results in a large foredeck - an important outdoor space - large enough to fit deck chairs.

The aft end design of the hull results in a much more useable space for arranging machinery and equipment - resulting in a space that is easy to access and maintain all of the mechanical systems needed on a modern boat.

All of the aft end layouts are still possible as the hull above the waterline is not impacted by our design approach. So ‘Trad’, Semi-Trad’ or ‘Cruiser’ stern options are still possible. The aft machinery space is the same length as on existing designs.

So whilst the Floating Ohm design differs from the existing designs, the powering and manoeuvring as well as significantly better outdoor areas for resting or entertainment. Being electric offers a step change in the cruising experience by being quiet, controllable and economic to run.differences are largely aesthetic and do not generate negative handling, powering or stability. Indeed the design offers improvements in powering and manoeuvring as well as significantly better outdoor areas for resting or entertainment. Being electric offers a step change in the cruising experience by being quiet, controllable and economic to run.