Thursday 28 July 2011

Freshwater Pumps for Sailboats

Part of your sailing 'adventure of a lifetime' planning process will be selecting the correct freshwater pumps for your sailboat. Like everything else these days it is not as simple a process as it has been in the past when you could go into a chandlery, ask for a freshwater pump for you boat and probably be handed the only pump available.
Nowadays there is a whole raft of models to choose from so you need to take into consideration all of your and your vessels' requirements. The following article from Kurt Kupper of  outlines some of the features that you need to check for before making your selection: 

'On any sailboats other than day sailers or runabouts, fixtures that allow the convenience of water on tap for showering, hand washing and dish washing are no longer considered a luxury. Driving these systems are freshwater pumps.

The most commonly used fresh water pumps used on boats are electrically driven diaphragm pumps. These are ideal for this application, because they are self priming, operate fairly quietly and can be run dry without immediate damage to the pump.

These pumps have built in pressure switches which turn them on and off on demand. The pump thus pressurises the plumbing system that it is connected to until the cut out pressure is reached. The pressure switch then opens to switch the pump off. As soon as a tap is opened and water runs from the system, the pressure in the system falls and the switch closes for the pump to run again. The pressure switches typically maintains a system pressure of about 3bar.

The immediate problem with this system is that when a tap is opened, there is a delay until the switch has been activated and the pump has sped up to restore pressure to the system. This results in uneven water flow. To counteract this, accumulators are often fitted into the system.

Accumulators are usually cylindrical tanks with spherical ends with a capacity of one up to twenty litres. At one end a connection is provided to allow water into the tank. At the other end is an air valve which is connected to a bladder inside the tank. This bladder is pressurised with air. When there is no water pressure, the air pressure in the bladder inflates the bladder like a balloon. When the water pump is run, water enters the cylinder and compresses the air in the bladder. Whenever the water pressure in the system starts to drop, the bladder can expand again, thus keeping the water circuit pressurised. This has a dampening effect and results in more even water flow.

Recent pump developments have brought us pumps fitted with sophisticated electronic control units that regulate the speed of the pump instead of just having a simple pressure switch. These are very responsive to fluctuations in water pressure and can be used without an accumulator in the circuit, yet produce flow smoother than in systems fitted with an accumulator. As can be expected, these pumps are somewhat dearer.

Pumps are available with different flow ratings. Although there are some baby pumps suited just for one washbasin that pump about 4L/min, most boats are fitted with pumps capable of supplying between 10L/min and 25L/min. At the lower end of this range these are suitable for boats where it is unlikely that more than one outlet will be used at any time. Boats with multiple showers and basins require larger pumps to ensure that water pressure and flow are maintained if several taps are run at the same time.

When selecting a pump, carefully consider what your pressure, flow and voltage requirements are. The more pump chambers the product has, the smoother the flow is likely to be.

Diaphragm pumps are very susceptible to dirt and therefore require protection by fitment of a fine strainer before the inlet to trap any contaminants. These are often supplied as standard with the pumps and should be cleaned regularly to ensure optimal performance.

The pipe connections on pumps are sized relative to the flow they are capable of producing. It is important to note that larger pipes should be fitted throughout the system when the larger pumps are used, as the benefit of their capacity will otherwise be lost through restrictive resistance. Great care should be taken to ensure that all joints in the pipes are carefully made and don’t leak. Leaks in the system will cause the pressure to fall, resulting in the pump being automatically activated periodically to boost the pressure again. This can be most annoying, especially at night.

As with all electrical equipment, use only tinned cable of adequate cross sectional area to wire up pumps, make sure that the joints are protected from moisture and fit a fuse or circuit breaker with a rating corresponding to the manufacturer’s recommendation'.

Article and images courtesy Kurt Kopper

You can read more about boat pumps and their repair whilst on passage in my ebook 'Voyage of the Little Ship Tere Moana' downloadable from my website

Tuesday 26 July 2011

ARC 2011 Cruising Sailboat Preparation

Having completed the Atlantic Rally for Cruisers two  times - once as crew and then five years later in my own yacht 'Tere Moana' -  I can thoroughly recommend it as the most wonderful way to set sail on your 'Adventure of a Lifetime', sailing off over the horizon to sail and explore the many oceans of this beautiful planet of ours.

The ARC gives a great insight into planning for an extended voyage, plotting your course, provisioning, navigating, safety at sea and much much more. There are many seminars that you can attend plus practical courses as well. Plus there is the additional benefit of meeting so many other like minded folks at these sessions - not to mention the social functions! - many of whom will become lifetime friends. 

It is a mighty experience, the memories from it being cherished forever.

This year there will be approximately 240 vessels sailing from the start line in Las Palmas in November, to the finish in St.Lucia sometime before Christmas. It is fully booked for this year, but 2012 could be your year?   

The following extract tracks the preparation of a group of Welsh sailors in their preparation:

'Every year for over 20 years, enthusiastic sailors have ventured from all parts of the globe to join the ARC, or Atlantic Rally for cruisers. Some of these come back year after year, but many others are starting on one of the greatest sailing adventures of their lives so far, crossing the Atlantic Ocean. This is the case for five hardy Welshmen, who are determined to cross this year in the great rally.

Their adventure which will take them from South West Wales to Portugal and then on to Gran Canaria for the start of the rally on 20th November, heading for the Caribbean.

The intrepid sailors, skippered by Ian Williams, left Swansea Marina yesterday aboard the Arabella, a 39ft Bavaria yacht.

Some 240 boats from around the world will be taking part in the event — but the Arabella is though to be the only Welsh craft involved.

The fearless five have spent the past 15 months preparing for the rally and getting their floating home in ship-shape condition.

The first stage is to get the Arabella to Lagos near Faro in Portugal, then later in the summer it will be sailed down to Gran Canaria ready for the starting flag in November'.

More about the ARC:

This annual transatlantic rally starting each November in Las Palmas de Gran Canaria, has now become a very popular way to cross the Atlantic, particularly for first-timers. The largest transocean sailing event in the world, every year the ARC brings together over 200 yachts from all over the world.

The Caribbean destination is Rodney Bay in Saint Lucia, one of the most beautiful islands in the Lesser Antilles. The 2700 nautical mile passage on the NE tradewind route takes on average between 14 and 21 days.

Conceived as a friendly race for cruising yachts to make the Atlantic crossing both safer and more enjoyable, participating yachts must carry a range of safety equipment including a liferaft, EPIRB and VHF radio.

Daily radio nets contribute further to the safety of participants. The presence of experienced sailors is another incentive for those with little offshore experience.

The ARC has a special flavour, which successfully combines racers with cruisers, old with young, and provides entertainment for all. A wide ranging programme of entertainment takes place both before the start and after the finish. The ARC enjoys the support of the Tourist Authority of Gran Canaria, the Port Authority of Las Palmas, Rol Nautic and the Saint Lucia Board of Tourism.

For more information go to their website

You can read many more ARC exploits and adventures in my ebook 'Voyage of the Little Ship Tere Moana' downloadable from my website

Monday 25 July 2011

Halyard Lines: Lancelin Introduce New Millenium Cord for Sailboats

Halyards, like any other lines on your sailboat need replacing from time to time. Cordage companies are constantly researching and developing new and better products. Lancelin of France is one of the leaders in this field and have just launched their 'Millenium' product which is especially suitable for halyards.
'When next you are wanting to replace your aging halyards, there's a new line to check out. French rope manufacturer Lancelin have brought out Millenium, a new rope suitable for halyards. It is the combination of two fibres in the core that makes this a high performance rope with extremely low creep.

It is very pliable with a very good hand, easily spliced and excellent for halyards.
It also confers a good tension and abrasion resistance and ensures a good performance in jammers.

Technical specifications of the composition:
Cover: 24 plait Vectran® or aramid Technora® braid and polyester.
Core: 12 plait Dyneema® SK 75 and high modulus Vectran®.

Interesting in knowing more? If your local marine store cannot help you, Lancelin will be able to tell you where your nearest stockist is if you complete this form.

About French company Corderie Henri Lancelin:
Founded by Joseph Lancelin in 1917, now managed by Nicolas LANCELIN, fourth generation in the business, continues its progress in the world of yachting.

A hundred years of experience and research have allowed Corderie Henri Lancelin to reach an expertise in the manufacture of high-tech ropes and to develop an ability to respond to specific demands, either technical or aesthetic.'

Extract and image courtesy of Corderie Henri Lancelin, France

You can read more about halyard lines and rigging lines in general in my ebook 'Voyage of the Little Ship Tere Moana' downloadable from my website