Southerly 110 Keel

The Southerly Keel

How it works, how to fix it and some tips & tricks.

The sections of this booklet are . . .

Page 1 Introduction.

Page 2 The keel, how it works.

Page 3 When the keel is lowered.

Page 3 When the keel is raised.

Page 4 Before working on the keel or pennant.

Page 4 To shorten the pennant.

Page 5 To lengthen the pennant.

Page 5 To fit a new pennant.

Page 6 To change the hydraulic oil.

Page 7 Keel slowly drops.

Page 7 Leaking High Pressure hydraulic hose.

Page 8 Keel Electronics.

Page 8 Tracing Keel LED faults.

Page 9 Two keel control points.

Page 10 Adjusting the keel LEDs.

Page 10 Tips and Tricks.

Page 11 Contacts & Data.

Page 13 End.

Introduction.

This text focuses on the Southerly keel, not because they are unreliable, but because they are unique and few
people understand them. The number of problems when related to the number of systems in use and the many
years they have given trouble free service proves they are most reliable, and Southerly owners will attest to this
fact.

I have written, maybe too much already about the Southerly lifting keel and its electro-hydraulic system, I have no
qualifications to do so. If you have a technical hydraulics problem then first look on the Southerly Owners
Website, it is a great source of knowledge, information, tips and tricks. Then if you cannot find answers, post your
own thread, remember to quote boat model and year and all the details, of the part and the problem you have. Also
look directly to Discovery Yachts (the builders), Northshore Yachts (former builders) or direct to the
manufacturers of the particular parts if their details are known, most of them like Wema and Fluidlink Hydraulics
are very helpful, and pleased to supply parts and/or service and repair. See “Contacts & Data” on page 11.

This text extends my original post of January 2016 "S110 Lifting keel.pdf", and the extensive thread that followed
with very useful posts from Southerly owners. It is based on the experiences I had with my brother John and his
1991 S100 and more recently on my friends 2002 Southerly 110 “Sirocco”. In the last five years I have also
learned more about this subject, from owners on this forum, from my friends and their boats and by studying the
available data to help me make suggestions in reply to questions on the SOA forum.

Of late I have found the Northshore document “Northshore Keel Operating.doc” helpful, re-posted recently
here :- http://www.soa-forum.org.uk/forum/download/file.php?id=1299. This document is particularly useful
because on the first page it details the schematic “Hydraulic system 04/’06 for All Southerlys” and a description
of how to operate the keel hydraulics, electrically and manually. Most items in the schematic are annotated but
not all of them, it can be helpful to remember what the symbols mean, e.g. one that looks like )( indicates a “Flow
Control”, usually a restriction of the oil flow in one direction only with free flow the other way. On the second page
is a drawing of the S42 keel & hydraulics, if your boat is not a S42 this drawing is of limited use. However it is
worth keeping a copy on board, just for page 1. I also have a copy of schematic Drawing No. FL5381 from Fluidlinks
Hydraulics.

Page 1 of 13

Finally, if you find errors in this document or contradictions with one or more of my previous posts or would simply
like to point out where I get it wrong, then email me, or better still, raise it on the SOA Forum so that all who wish
may get involved.

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The keel, how it works.

The Southerly keel is raised and lowered utilizing a
modern efficient electro-hydraulic system that
incorporates a double acting hydraulic ram, but
only one end is used under pressure. There is a GRP
box that contains the main unit and sub-assemblies,
so that if there are any leaks or spills most of them
will be caught in the box and are easy to clean up.
The GRP box contains the hand pump and lowering
valve for manual movement and the Stop Valve
Assembly.

The switch or switches that operate the keel are
at the binnacle and are controlled from the helm
position. Some Southerlys have two control
positions so that the keel can also be raised or
lowered electrically from below. This is very useful,
making it easier to adjust the level of the keel when inserting the pin.

In my simple schematic drawings here of the
hydraulic system, please note; the red “High
Pressure” hoses are those that are always high
pressure, while the system is pressurised. The
grey hoses can be high or low. The green “Low
Pressure” hoses never have more pressure than
that caused by friction.

At the helm position in the cockpit there is a
small keel control panel which includes an
up/down switch (or up & down buttons) and a set
of LED lights that indicate the keel’s current
position.

If the boat is being left for several days or
longer it is best to raise the keel, insert the pin
and lower the keel onto the pin. This is done for
a number of reasons,

1. To remove the tension on the keel pennants and to minimise stretching.
2. To minimise the strain on the keel pivot bearing. With the keel down the keel reduces the amount of roll in

high winds, but this incurs stresses on the keel pivot, which can be avoided.
3. To make sure the keel is not sitting in deep mud. If a cast iron keel is left in deep mud for some time, it can

corrode rapidly (graphitic corrosion).
4. To minimise the amount of fouling that builds up over a season.

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When the keel is lowered.

The solenoid valve in the pump unit opens, releasing the high pressure oil, but only slowly through the stop valve and
the built in flow controls. Without the stop valve and flow controls the one tonne keel would drop very quickly and
probably do some damage. With the solenoid valve open then gravity lowers the keel until it is stopped by the
grounding plate or the sea bed unless it is stopped by the operator before that.

As the keel is lowered the expelled oil is drawn by suction into the lower section of the ram. So with the keel fully
down the piston within the ram will be at its highest normal position and the lower part of the ram full of oil. If the
keel is resting on the grounding plate, the oil in the top part of the ram will be under only slight pressure. You can
adjust the speed of descent by adjusting the stop valve which must only be adjusted when there is no pressure on
the system. Full open is the fastest and it will take a S110 about 30 to 40 seconds to drop at this setting, fully
closed and the keel will take about 60 to 70 seconds to drop. Most Southerlys are, I believe set near the full open
position, but if yours drops too quickly, with a bang when it reaches the bottom then close the valve a little. Maybe
also check the hydraulic oil?

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When the keel is raised.

The pump delivers oil from the reservoir under high
pressure to the high pressure end of the ram, the ram is
forced to contract pulling the pennant which in turn lifts
the keel. This action causes the oil in the lower section
to be expelled back to the reservoir, replenishing the oil
as it is withdrawn by the pump.

When the keel is fully up the excess oil pressure causes
the overload valve to blow off, returning the oil to the
reservoir and making a noise that along with the LEDs,
warns the operator to stop lifting.

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Before working on the keel, pennant or hydraulics.

Before starting to work on the keel it is a good idea to stuff some old shirts or rags in large plastic bags and use
them to fill the space around the keel. So that anything dropped is easily retrieved.

Always use good ring spanners or sockets on the stainless steel nuts and bolts to do with the keel. Be aware of
“Galling” always remove bolts and apply a smear of molybdenum disulphide grease to the bolts and on the threads in
the holes before reassembling. See reference to Vyv Cox’s book under the heading Tips & Tricks below. If you
don’t have “Molly” grease then water resistant grease is much better than nothing.

A cautionary note for those about to do some repairs or maintenance on their Southerly keels. Even on the S100
the keel weighs over a tonne. The working pressure of the hydraulic unit shown here is 150 BAR (2,175.5 psi) or
thereabouts. Make sure that the keel is secure and properly chocked up if not resting on the pin, the ground, or
the grounding plate (full down). Make sure that high pressure hydraulics have been relieved before doing anything
with the hydraulic system.

There is normally less air in the system if the inlet and outlet ports of the ram are on the uppermost side.
Therefore if you are going to do anything that involves removing the hydraulic ram it is worth making sure the
ports are on the uppermost side. Also make sure the replacement is well painted before fitting.

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To shorten the pennant.

If the keel cannot be lifted enough for the pin to be inserted then the pennant will need to be shortened. But first
make sure the problem is not caused by something in the keel box. Shortening the pennant is almost impossible if
the keel is fully down (resting on the grounding plate), it is probably best done ashore. If you chose to do it while
dried out then be sure you have enough time before the tide comes back in.

1. Read the above notes “Before working on the keel or pennant”.
2. First mark the pennant the distance you wish to shorten it from the stopper. It is easy to lengthen so err on

the short side.
3. Open the manual lowering valve and leave open.
4. In order to shorten the pennant some loose has

to be created, this is not easy because of the
oil flow restriction in the system. Use a lever
on the pennant to create some loose, do not be
surprised by the force required to do this.
5. Loosen the bolts, 1,2,3 and 4 in the picture, you
may have to remove 5 in order to get No. 1 out.
6. Adjust the length of the pennant, so that your
mark comes close to the stopper.
7. Before replacing the bolts smear some
molybdenum disulphide grease on the bolts and
on the threads in the holes.
8. Replace and tighten up.
9. Close the manual lowering valve.
10. Check if you can now raise the keel enough to insert the pin, if you can then also check that the fully lowered
keel is resting on the grounding plate.

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To lengthen the pennant.

If the keel when lowered, hangs on the pennant and does not reach it’s resting place on the grounding plate then it
needs to be lengthened.

This can be done while the boat is afloat providing the keel is resting on the pin or the ground and is not suspended
on the pennant. It can also be done while ashore, the snag with being ashore is that you may not be able to lower
the keel fully to check if you have extended the pennant enough, until you next launch.
Decide before you start how much you are going to lengthening the pennant. Bear in mind that a pennant two
inches longer will mean the keel will only drop one inch more, there is a two to one leverage. Also only change a
little at a time because it is easier to lengthen than to shorten. If lengthened too much then you may not be able
to release the pin. If this happens then shorten the pennant a little.

1. Read the above notes “Before working on the keel or pennant”.
2. First mark the pennant right up close to the stopper as in the

picture.
3. Open the manual lowering valve and leave it open.
4. Loosen the bolts, 1,2,3 and 4 in the picture, you may have to

remove 5 in order to do this.
5. Adjust the length of the pennant.
6. Before replacing the bolts smear some molybdenum disulphide

grease on the bolts and on the threads in the holes.
7. Replace and tighten up.
8. Close the manual lowering valve.
9. Check if the keel will now lower onto the grounding plate.

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To fit a new pennant.

It is best if your boat is ashore with the keel part way down and resting on the ground. You need to be able to undo
the two bolts that attach the pennant to the aft end of the top of the keel, shown in the picture.

1. Read the above notes “Before working on the keel or pennant”.
2. Make sure both ends of your new pennant are properly heat sealed.
3. The two bolts in the keel (marked in the photo) are normally under water when the keel is down, therefore

they need special treatment, apply WD 40 or similar and leave for a while to help to remove them.
4. When fitting keep any excess pennant at the top end and do not shorten it until after the job has been

completed and tested.
5. Before fitting a new pennant note how the old one is fitted at both ends. At

the keel end, it has a round turn (part clove hitch) around the top bar in the
photo and then a round turn around the clamping bar.
6. Before replacing the bolts smear some molybdenum disulphide grease on them
and on the threads in the holes, Locktight, Lockthread or water resistant
grease could be used. The object is to stop water penetration of the threads
and therefore reduce corrosion and make the bolts easier to remove next time.
Take extra care not to drop the clamping bar or either of the bolts into the
keel box. When the new pennant has been attached to the keel then place some
more rags in plastic bags on top of the keel.
7. Feed the new pennant through as the old one was and replace the clamps and
bolts at the top end. Estimate the active length of pennant required making it
on the short side, but do NOT cut it. You will almost certainly have to adjust
its length later, and it will be easier to make it longer than shorter.
8. Turn off the manual lowering valve.
9. Now try lifting the keel and see how it works, adjust the length as required.

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Even if you use pre-stretched Dyneema you can expect it to stretch further in use, so you will probably have to
shorten it again. After a further period of use it will stop stretching.

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To change the hydraulic oil.

Approximately five litres of new oil will be required for an S110. I don’t think it is necessary to change the oil
every four years as has been suggested, maybe after eight or ten if necessary. However I would change it as soon
as possible if I suspected that it was contaminated with condensation, the wrong type of oil or other material or if
it had been used when low in oil thus foaming or becoming aerated or if any other problem had occurred. Oil
suppliers will generally recommend replacement more frequently than necessary. If you are not sure then get the
oil tested, or change it, we are not talking about a great expense and it will normally be infrequent.

If the oil needs to be replaced, then all the oil should be replaced, that includes draining both ends of the
hydraulic ram and the reservoir. Changing the oil is not all that difficult, you should be able to do the job without
direct access to the ram, (thank goodness for that I hear you say) it can all be done from within the GRP hydraulics
box and with access to the top of the keel.

Normally the hydraulic system does not need bleeding. But if the pump has been run when dry or after an oil
change it may need bleeding, if it does then you will probably have to bleed the manual pump also. Once you have it
pumping again then any problematic air in the system will be removed automatically, however in this situation check
the reservoir frequently, because not all of the air will necessarily be expelled in the first cycle.

So to change the oil . . .
1 Make sure the hydraulics are not and will not have any pressure applied while working on them.
2 To do this, raise the keel, insert the pin and lower onto it. At this point the piston will have already expelled all

or nearly all of the oil in the low pressure end of the ram.
3 Open the manual lowering valve and leave open, so that as much pressure is taken off the system as possible.
4 Drain as much oil as possible from the pump reservoir, a Pella sump extraction pump is good for this.
5 Mark the high pressure flexible hose in the keel box that connects to the ram, so that the hoses may be

replaced correctly. See the first photo of the keel box on Page 3.
6 Undo the two flexible hydraulic pipes in the keel box that connect to the ram, a little oil may flow immediately

from the high pressure pipe. You could catch this and the subsequent greater volume with a large container.
7 Move the ram to the fully extended position by pulling the keel pennant. The oil in the high pressure end will

be expelled through the high pressure hose in the keel box where it could be collected in a container. This will
not be so difficult as when trying to adjust the pennant.
8 Remove any oil that has drained into the reservoir. Reconnect the pipes and close the manual lowering valve.
9 Refill the reservoir to the top.
10 Raise the keel, partly electrically and partly manually and top up the reservoir level before it is fully raised.
This will ensure that the high pressure end is full of oil, and the pumps do not run dry.
11 Refill the reservoir again when fully up.
12 Lower the keel. On lowering, the oil in the high pressure end of the ram will be transferred to the low
pressure end, so check the reservoir, it may need topping up.
13 Lift the keel and then check the oil again. The oil self bleeds but not necessarily completely the first time.
14 The system cannot self bleed if there is not enough oil in the reservoir, and low oil levels can cause serious
problems.
15 The ram contains less oil when the keel is fully up (the ram fully contracted), because of the volume of the con
rod inside the ram, therefore the reservoir is fuller at this time. It follows that the best time to top up the
reservoir is when the keel is up. If it is over full it will spill into the GRP box through the breather/filler cap,
when the keel is fully up. This is not a problem except for the mess of a small amount of oil in the box.
See “Contacts and Data” near the end, for details of oil specification and suppliers.

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Keel slowly drops (if held up on the hydraulics without the pin in).

First check there are no hydraulic leaks that can be seen in the system including the hydraulic pipes and the ram.
If nothing is found then the problem has to be internal, within the ram, and/or within the equipment in the GRP
hydraulic keel box. It is best to start by isolating the ram to ensure the problem is not there. To do this you will
need a simple hydraulic ball valve with a minimum working pressure of 150 BAR. Obtainable from your local
hydraulics service station or online, like this one.
https://uk.rs-online.com/web/p/hydraulic-ball-valves-line-mounting/2975827/
This is £15.12 inc. VAT & Free next day delivery but you will also need the necessary connections to enable
temporary installation.

It is not difficult to temporally fit a valve between the high pressure hose and the Stop Valve Assembly, so as to
enable a simple test. To fit the valve lift the keel and insert the pin, lower the keel onto the pin, then open the
manual lowering valve.

Now it is safe to undo the connection
where indicated, with minimum loss of oil,
so as to fit the temporary valve in “No. 1”
position.

Run the test. Make sure the temporary
valve is open, and close the manual
lowering valve, raise the keel and then
close the temporary valve, while still
holding the keel suspended and watch. If the keel slowly drops then the problem is within the ram or the
connecting high pressure hydraulic hose. So open the temporary valve, lift the keel, insert the pin and lower onto
it, now remove the temporary valve, and reconnect as originally.

If the ram is the problem it is probably best to take the ram out and have it serviced, if you have to have a new or
replacement ram make sure it is one with a stainless steel connecting rod. After replacing the ram go through the
procedure detailed above under “To change the hydraulic oil”.

If it is not the ram, then the problem is within the GRP hydraulic box. You can narrow it down further by carrying
out a similar test on the Hand Pump Assembly. Insert the “No. 2” temporary valve in the high pressure hose to this
unit, the photo indicates the valve at the Stop Valve end of the hose, only because it is easier to do it this way. If
it is fitted at the other end of the hose at the Hand Pump Assemble then make sure it is fitted to the lower (high
pressure) port.

As before make sure there is no pressure in the system before you start. When valve fitted in No.2 position then
turn both the lowering valve off and the temporary valve valve off, N.B This is different to the first test.
Lift the keel and if the keel does not slowly drop then you know the problem is in the Hand Pump Assembly, which
could be returned for service/repair.

If the keel continues to slowly drop then it must be in the main Pump, Valve & Reservoir Assembly or the Stop
Valve Assembly. It is more difficult to narrow it down further so it is probably as well at this stage to send both
of these items back for service/repair. See contact details at the end.

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Leaking High Pressure Hydraulic Hose while at sea.

If a leaking high pressure hydraulic hose lets the keel drop while at sea and if is absolutely essential that the keel
be raised in order to get back in to a safe haven. Then you can probably make a temporary repair while still at sea.
It will not be easy and requires access to both ends of the hydraulic hoses, in the GRP hydraulic keel box and at the
ram. On the S110 the access to the ram is on the port side of the keel and it is quite difficult to get at, below the

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galley sole and inboard of the calorifier. If you can anchor in a safe deep water place for a few hours it would make
this temporary repair a great deal easier. To make the repair . . .

1 Mark the broken high pressure hose at both ends but not the low pressure hose.
2 Open the manual lowering valve so that as much pressure is taken off the system as possible.
3 Undo both hydraulic hoses from the unit in the hydraulic box.
4 Undo both hydraulic hoses from the ram.
5 Reconnect the low pressure hose where the high pressure hose was at both ends.
6 Tape up the leak of the old high pressure hose as best you can before connecting where the low pressure hose

was. It will probably still leak but not very much because it is only very low pressure.
7 Fill the reservoir (to the top).
8 Turn off the manual lowering valve.
9 Try to raise the keel, if it works lift it and insert the pin, if not then lower it, check the oil level and try again.
10 If you are successful and get the keel to the top then insert the pin, and lower onto it.
11 If it is really important that you get the keel up and the only oil you have on board is engine oil or gear box oil

then use the thinner of the two, but make sure that all the oil is changed to the right specification as soon as
possible.

When ordering new hydraulic hoses always specify thermoplastic cord base (Synflex, Parflex, etc) these are
entirely reinforced with synthetic fibers. This is an advantage in a marine application. See Contact & Data for
more details. Dispose of the broken hose but keep the good hose as a spare.

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Keel Electrics.

The switch(es) that operate the keel are at the binnacle. Some Southerlys have
two control positions so that the keel can be raised or lowered electrically from
below as well as on deck. This can be very useful and can easily be added.

As the keel is lifted the LED lights change colour so the operator can see how far up
it is. When fully up the overload valve releases the excess oil back to the reservoir
and the noise of this together with LEDs ensures the operator stops lifting. As the
keel is lowered the LEDs change back.

In the photo (below) you can see the most important parts of the sensing
mechanism.
The LEDs are controlled by sensors in a long 10mm stainless steel tube alongside
and fixed to, the ram, it does not move. The white plastic block has magnets within,
and is attached to the turning block and slides up and down the tube with the
movement of the turning block and therefore with the keel.
The sensors in the tube change their electrical resistance as the magnets are moved over them.

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Tracing keel LED faults.

In the image there is a table of resistance figures in Ohms, these are the changes to the resistance that the
sensors make as the magnet passes over them. By using a voltage meter you can measure these resistance figures.
Note the keel is not fully raised until after the top Green LED has lit. So in order to sort any electrical problems
with the sensor, one needs to be able to measure the changing resistance.

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This is easy to do from the cockpit display, but bear in
mind the resistance will be a little greater in the
cockpit. Simply disconnect the two wires that come
from the sensor and use a volt meter set to measure
the Ohms resistance (set at 20k), check the resistance
at various stages of the keel from fully down to fully up
and you should have readings similar to the table.
If these readings do not check out then you will need to
get to the bottom of the ram to check the sensors
from there. If they are correct at the ram then there
is a fault between here and the binnacle, if not then
check the operation of the magnet as already detailed.
If you still cannot find the fault then the sensor itself
is suspect and it would be best to return it to Wema.
These details refer to keel controls and sender unit
originally supplied by :- Wema UK Ltd., see Contacts
and Data below.

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Two keel control points.

This diagram is split into three parts, control panel, keel box and binnacle.
If your Southerly does not have a second control position for the keel electronics then it is worth fitting one. It
can be added just below the main control panel, or wherever you wish, so that the keel can be lifted or lowered
from inside the boat, making it much easier to insert or remove the pin. Sooner or later you are going to want to
adjust or replace the keel pennant, this also is much easier to do if there is a second keel control switch near the
keel. With the top off the keel box you can see what you are doing, when raising and/or lower the keel.
It makes sense to move the keel isolator switch at the same time, so that it can be turned off without having to
open the keel box. The small fuse remains in the keel box.

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To ensure the switch cannot be left on, it is necessary to fit a Single Pole three position switch “Flash-Off-Flash
SP Metal Toggle Switch - 15A”. As per this example. http://www.furneauxriddall.com/cgi
bin/sh000004.pl?WD=sp%20toggle%20switch%20metal%20flash%2doff%2dflash&PN=Metal%2dToggle
%2dSwitch%2dSP%2d%2dFlash%2dOff%2dFlash%2d%2d316_852%2ehtml#SID=416

When adding or altering wiring, I always try to think of all possible
future scenarios. For example what would happen if the helmsman
decided to let the keel down at the same time as an internal crew
member raised it? Well in this case nothing untoward, the lowering
valve would open at the same time as the hydraulic pump would work,
the only thing achieved would be the battery drain required to run
the motor.
With reference to using the diagram above.
1. Firstly this was how we set it up in “Sirocco”, your system may be

different, but it should be similar.
2. The diagram has three shaded areas, the left one is the new

wiring just below the Control/Fuse Panel, the middle one is in the
Electro-Hydraulic control box and the right one is the wiring at
the binnacle.
3. If your system only has three wires from Binnacle to the Electro-Hydraulic control box it does not matter.
You can do without the negative (black) wire providing there is a good negative connection at both places.
There should be because it worked before.

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Adjusting the keel LEDs.

With Sirocco (S110) I don’t know about others, it is not possible to adjust the space between the LEDs. The 10mm
stainless sensing rod with sensors within is fixed alongside the hydraulic ram. However you can adjust how far up
or down the sensing rod is fitted, thus moving all the LEDs higher or lower.

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Tips and Tricks

Be careful with difficult to undo stainless steel nuts and bolts, particularly the stainless steel ones to do with the
lifting keel. Most of these bolts are threaded into stainless steel and there is a particular problem with this in a
marine environment, called “Galling”. More details under Contact and Data below, but I have seen a bolt sheer
clean off because of it.

My method of dealing with these nuts and bolts is as follows . . .
1. Whatever you do, don’t damage the heads of the bolts.
2. Only use the correct socket or correct large ring spanner (no adjustables) a lot of pressure can be applied to

the large bolts.
3. I would NOT advise applying heat, apart from the obvious problems of toxic fumes and fire hazard in such a

confined space, there is also little hope of success. When heat is used in a more open space, it needs to be
applied to the surrounding metal. This needs to be heated up considerably and the bolt heated with it, then
when the metal is red hot, the surrounding metal is cooled as fast as possible with flowing cold water, so that
it shrinks rapidly onto the hot bolt before the bolt also cools and shrinks away from it. Never try to take the
bolt off when it is hot, you will probably sheer the bolt and you may ruin your socket. Also, applying cold water
to a hot cast iron keel is never a good idea. Cast iron is very brittle and you could crack it (very expensive).
What is more, it is such a massive bulk of metal you will probably not get it red hot, and I would not want to be
involved in anyway if you did.
4. If you are unfortunate enough to have to resort to drilling out a broken bolt, then bear in mind that stainless
steel very quickly becomes work hardened. So make sure you use only new or very good condition high quality

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cobalt tipped bits and ensure the work is well lubricated, during relatively slow speed high pressure drilling.
Do not let the bit overheat.
5. If you have started drilling then make sure you complete it, if you fail half way through and leave it, then it will
be more difficult in a few years time.

Finally to ensure galling does not happen to you in future. Always remove the bolts completely and before replacing
them smear both threads with molybdenum disulphide grease, sometimes called Molly grease.

Galling. This is described in detail in Vyv Cox’s book “Metal in Boats”, the author is a chartered engineer with
specialisms in metallurgy and mechanical engineering. Galling is a type of seizing where salt air and moisture have
an effect on the surfaces of stainless steel that involves the two pieces of metal becoming effectively welded
together. The book also details Galvanic corrosion, Fractures, Joining metals, etc. etc. A great deal about mooring
chains, anchor warp, anchors etc. The author has spent many years cruising in small boats, well worth £22.50 in my
opinion. ISBN 978-1-78500-262-5.

Someone on the SOA Forum suggested washing off the keel pennant turning block at the top of the keel box with
warm fresh water from time to time. I think this makes a great deal of sense, the warm water will dissolve any salt
and wash it away, otherwise it crystallises and can cause a problem.

Flow Control. Near the beginning I mention this symbol )( indicating a “Flow Control”, usually a restriction of the
oil flow in only one direction with free flow the other way. This can be contained in a separate fitting, on my
brother’s S100 someone had replaced it the wrong way around, and had failed to correct the problem. The system
would raise the keel only very slowly and with great difficulty, but it would fall and hit the bottom with a bank. All
we had to do was turn the flow control the other way around.

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Contacts & Data

You will find it helpful to make notes of names and contact details, part nos, serial nos, etc., of all the equipment

you have on board, particularly the electro-hydraulic unit and other things fitted to your boat.

Discovery Shipyard Ltd., Unit 5, Harbour Close, Marchwood, Southampton SO40 4AF

HEAD OFFICE - Lymington Yacht Haven, King's Saltern Road, Lymington SO41 3QD

Builders of Southerly yachts since 2017 also builders of Discovery 55’s 58’s and Bluewater catamarans.

Tel: 023 8086 5555

Email: [email protected]

Website: https://discoveryyachtsgroup.com

Northshore Yachts, Itchenor, Chichester, West Sussex PO20 7AY, England

Builders of Southerly yachts for nearly 40 years, between 1975 and 2014, also builders of Vancouver, Fisher and

Supermarine boats.

Tel: +44 (0)1243 512611

Email: [email protected]

Website: www.northshore.co.uk/

Wema UK Ltd. The sensors, LED units and the electronics that control the LEDs, fuel gauges etc.

Tel: 01404 88 18 10

Website: http://www.wema.co.uk/

Email: [email protected]

Email: [email protected]

Wema also supplied the table of resistance detailed in “Tracing Keel & LED faults”

They are very helpful if you need to contact them.

Fluidlink Hydraulics Ltd., supplied the hydraulic system for the 2002 S110 “Sirocco”, is yours the same?
This company is also very helpful and have a service and repair system.

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Unit 6. Hopton Court, Hopton Industrial Estate, Devizes, Wiltshire, SN10 2EU

Tel: 01249 818 555

Email: [email protected]

Website: www.fluidlink.co.uk

Specifically: www.fluidlink.co.uk/product/fs756-fs757-fs758-keel-lift-systems/

OR https://hydraulicsonline.com/product-category/brands/fluidlink-hydraulics/

Hydraproducts Ltd., current suppliers of the hydraulic systems. They also are very helpful and have a service and

repair system.

Mr Ben Lee MD

Unit 5&6 Tuffley Trading Estate

Pearce Way

Gloucester, Gloucestershire GL2 5YD

Tel: 01452 52 33 52

Email: [email protected]

Website: https://www.hydraproducts.co.uk/Hydraulic-Power-Pa

Email: [email protected]

Website: www.hydraproducts.co.uk/Contact-Us

The pennant. Specification for the Southerly 110 is

Type Dyneema, braid on braid

Length 4m

Diameter 20mm

Breaking strain 18 tonnes

Available from most riggers, sail lofts and chandlers, prices vary widely.

Hydraulics. Topping up.
The ram contains less oil when the keel is fully up (the ram fully contracted), because the volume of the con rod
within the ram displaces some of the oil, therefore the reservoir is fuller. It follows that the best time to top up
the reservoir is when the keel is up. I have had this wrong in the past.

Hydraulic RAMs. If ordering a new or replacement ram always specify one with a stainless steel con rod

(connecting rod) as well as checking the internal diameter, stroke length and maximum working pressure are within

the specifications. A reliable hydraulics service again will do all this for you. Available from many sources.

Hydraulic Hoses. When ordering new always specify thermoplastic cord base (Synflex, Parflex, etc) these are
entirely reinforced with synthetic fibers, this is an advantage in a marine application (no rusting if the outer
covering becomes damaged). Also available from many sources.

Hydraulic Oil. S110 hydraulic system specifications
Reservoir Capacity 5 Lt
Max Safe Working pressure 150 BAR 2,175.5 psi
Relief Valve setting 150 BAR 2,175.5 psi
Flow 3 Lt/p/m
Oil type 32 CST Hydraulic Mineral Oil.

There are a number of posts on this subject but as far as I can ascertain, Mike Howard’s post of 1 July 2020 fits
all that I can confirm. http://www.soa-forum.org.uk/forum/download/file.php?id=1299
In his post he said www.lubefinder.com had advised him that “Shell Tallus 37 has been replaced by Tallus 32”.

It makes sense that such a cool running system should have a viscosity of 32. My knowledge in this field is limited
but the following may be of interest :-
ISO (International Standards Organisation) is a very widely accepted standard.
SAE (Society of Automotive Engineering) is also a widely accepted standard.

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AW (Anti Wear) is usually to ISO standard with anti-wear and reduced rust and oxidation additives.
The number following the above prefix is generally the viscosity of the oil, lower numbers for thinner oils used in
colder climates and higher numbers for thicker oils, used in very hot countries or when systems are subject to
extended use with excessive heat over long periods of time.

The Southerly hydraulics systems are used very lightly compared to normal industrial use, and are always in the
coolest part of the boat, low down, in the shade, near the water, so a thinner oil should be preferable.

Dave Kitson, said on the SOA forum » 14 Jul 2020
A little off topic but - with the keel partially up, as it will be in the canals, particularly avoid hitting underwater
obstructions at speed. We hit one as a barge passed us. The keel rode up then went back down with no apparent
damage. There was no hull damage BUT the keel slamming back down under gravity until the pennant went taught.
The un-designed-for strain on the keel box shattered it, which only became apparent when she was hauled out at
Northshore for what we thought was minor rudder damage from the same incident. VERY expensive and thank you
Pantaienius.

For more general and technical hydraulic problems not necessarily to do with the Southerlys see . . .
Hydraulic Supermarket, West Perth, Australia. Brendan Casey who is the knowledge behind this organization,
writes a regular technical news letter that I used to receive.
Website: http://www.HydraulicSupermarket.com
If you are interested in the hydraulics system then this is worth a read.
https://www.hydraulicsupermarket.com/6mistakes.pdf

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George Llewellin
Rock House
Sandy Haven
St. Ishmaels
Haverfordwest
Pembrokeshire
SA62 3DN
Tel: 01646 63 63 63
Mob: 07968 077 161 (Does not work at home)
Email: [email protected]

January 2021

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