Vessels operating in shallow canals all suffer from a phenomenon called squat. When a vessel travels through water she pushes water ahead of her. In order for there not to be a ‘hole’ left in the water it must return down the sides and under the keel of the craft. As the space under and to either side is restricted there is an acceleration in flow velocity between the hull and the solid boundary of the canal. The smaller this space, the higher the velocity. (Bernoulli effect

Having, in previous discussions, introduced the concepts of our differing approach to the hull design we now look at the effects on powering of these changes. The illustrations below are for 57’ narrowboats of equal proportions and both operating at 3.6 knots (4mph) above: wake of traditional 57 narrowboat with conventional swim below: wake of Floating Ohm 57 narrowboat with improved swim Note the marked difference immediately aft of the stern. The Floatin

We have previously discussed how we have dealt with the design of flow and pressure distribution at the bow. We now look at the critical design of the aft end of the vessel. The flow around the stern is of very great importance as this will influence not only drag, but also the propulsive efficiency of the propeller. In an ideal situation a propeller would prefer to have ‘clean’ water flow towards it without turbulence and at the same speed as the boat is travelling (Speed of

As discussed in previous sections, the ethos of the design of the bow can be seen to be similar to that of a Bulk Carrier, in that both vessels are looking to maximise internal volume, in our case to ensure the largest internal volume for accommodation, in the Bulk carrier it is clearly volume for cargo. Fuel consumption for the Ship Owner is paramount and in our case energy consumption for propulsion is also key - so further parallels in requirement. Using this design approa