How can I reduce the maintenance of my B&G Hydra system?

Steve Hayles answers...

Steve is most well known as an offshore navigator. He competed in 93-94 Whitbread Race as the youngest navigator in the history of the race, and since has been involved two other Round the World Races, most recently with the Volvo 60 Tyco as navigator. He started sailing professionally at the age of 15, after being thrown out of school, and has competed in the majority of offshore classics such as the Admiral's Cup, Fastnet, Sydney Hobart and transatlantic races. On land he is the Technical Director of Diverse Yacht Services. The company has developed products such as Racevision and supply electronic hardware and software to many of the top racing teams worldwide. Steve is currently working on developing a number of new products and software programmes in conjunction with partner companies and specific race boat projects.

Diarmuid Foley asks:

How can I minimise annual maintenance on my B&G Hydra system ?

My boat's electronic pack , on a Mumm 30 , requires frustrating regular maintenance work and calibration to keep it working. Typically we'll do 5 or six regatta's a year, each one requiring to transport the boat by road trailer.

Apart from replacing parts, wiring problems etc I find the biggest difficulty is having to re-calibrate the system between regattas ( something we are not particularly good at ! ). Typically we find we have to recalibrate the log and the MHU.

I accept that electronics in a salt water environment is always going to be problematic, especially on a ridiculously wet boat like the Mumm (TNZ doesn't know anything about taking water on board !) but I would appreciate your input in how to keep the costs to a minimum.

I have noticed one Italian boat that completely strips the 20/20 displays from the mast for transport.
Thanks for your help



Diarmuid,

It is good to hear that you are worrying about the calibration as it is an often forgotten part of any 'campaign'. We often find that problems do occur after unstepping and restepping a rig or having a boat out of the water for a while, which are quite often caused by wiring problems that occur when the connections for the masthead unit and 20/20 displays are broken to allow the mast to be removed. The signals coming down the rig from the masthead unit are fairly 'weak' and any problems with the connections at the base of the rig can show up as errors in the readings coming from the MHU.

When stepping and restepping the rig it is important that there is a reliable method to make and break these connections, a chocolate box or even a BandG style junction box will work but are not ideal in our experience. A 'custom' mast junction box designed for the boat with easy to use and most of all accessible connections will go a long way to making the system more reliable.

Any calibration errors in the system can be pinned down to three 'sources'. Firstly we might not have calibrated our instruments correctly or further refinement is required. This is often the case and calibration is an ongoing process but any errors due to having more work to do should at least be repeatable.

The second source is electrical / electronic problems which are often seen as not just calibration problems but apparent complete failure of the system. Unreliable connections can as I have said above cause problems that will show up as calibration 'errors'. These often show up in the wind angles as there are three cores of the cable coming down the rig that jointly carry wind angle information and the information is calculated from the relative output of the three cores so a bad connection in one core can cause hard to track and annoying problems.

The third source, which should not be overlooked, comes from mechanical problems. Two of three primary sensors (heading being the third input) are mechanical and as such any physical problems with these sensors will show up very quickly in the outputted data. The paddlewheel for the boat speed is a very common source of problems and nearly always these are down to mechanical problems in the movement of the paddlewheel within the housing. Leaving the paddlewheel in the water for any amount of time will cause very slight fouling (often not really visible) which will make big differences to the calibration. I would ensure that the boat has a blanking plug for the boat speed paddlewheel which is used any time the boat is in the water and not being sailed. BandG are about to launch a completely "no moving parts' sonic speed sensor which will have a number of advantages the most important of which in my view will be that the calibration will be extremely stable over very long periods of time.

I realise that we are trying to cut costs here but when the time comes to replace the paddlewheel consideration should be given to the new sonic system.

The same type of problems can often be seen in the masthead sensor, as there are small bearings in the both the angle and speed parts of the sensor, which are prone to problems over long periods of time as they wear out. Replacement bearings are available at low cost and they can be changed fairly easily. The biggest problem with the masthead unit is coming up with a reliable method to ensure that the unit is securely held at the same angle relative to the mast. This problem is most readily seen on boats with a vertical style carbon wand. These wands help a lot in getting the sensor above the upwash effects of the rig and sails but being circular in construction they often are attached to the rig by a female socket with the rotation being stopped by a pin or through bolt. This wears after time and when the wand is placed back in the rig there is no guarantee that it is i the same orientation as the previous time it was in the rig and calibrated.

The bottom line is that with the right connectors at the base of the rig and a little care to keep the sensors clean it should be possible to get the boat out of the water to the next regatta and back in the water without any calibration changes and with the minimal amount of effort.

I hope this is of some use.

Steve

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