275.5 Narrowboat runing hours with Mick & Brenda

Thank you for giving us the opportunity of trialling your Axiom prop and we hope the information below will be of good use to you. The prop was fitted on Monday 23 June 2008 when we had 178.8 hrs on the clock. You then removed it on Tuesday 2September 2008 with 454.3 hours and if our maths our correct the running hours calculate to 275.5

My positive observations are as follows:

• Stopping time fantastic – almost instantaneous.
• Reverse’s quickly and in a straight line – which helped on numerous occasions to avoid a collision with other boats approaching to quickly under bridges which made our trip less hazardous.
• Tick over 1000 R.P.M pushes the boat swiftly, without white water – and holds in a straight line.
• Quick to respond, both forward and reversing.
• When on sharp bends, using short bursts on the throttle it acts like a bow thruster on the stern, making it easier to steer round bends.
• t gave lots of control when approaching moorings.
• Easy to steer off tunnel walls.
• Prop still has good thrust at 1000 R.P.M even with weed around the shaft.

A negative comment:: On the canals as the water seems to be much shallower, the R.P.M over 1600 creates vibration underneath the boat and gives a feeling that the boat will go no faster – this occurs in deeper water at 1900 R.P.M.

Comments: I believe the water is possibly pushing through the centre of the blades close to the shaft rather then pushing over spread of the blades. Plus the length and width of the boat and being flat bottom creates some sort of water movement that has an adverse effect on the prop. Also at higher R.P.M creates a lot of white water.

Summary: I believe that Axiom props. Overall are superior to marine screw prop. Though I have highlighted a negative I am sure it only requires a little more ‘tweaking’.
Looking forward to speaking to you both when we return from our holiday in November and hoping we can still be of help with your trials. Maybe we can trial both props, under the same conditions on the same stretch of water over a given time, perhaps a couple of hours with both of you at the tiller. Mick & Brenda