Modernizing a Prout Elite 37ft

[atoll]

Originally Posted by Pete7

I hope she is well supported or he could end up building in an interesting "hog" into what was once a straight hull.

Pete

i don't think they are worried about stuff like that
otherwise they would not have chocked up the boat in the front under the sacrificial blubs on the bows

it will be a great learning experince for their next boat

[Snowgoose35]

According to one South African sailor I met those sacrificial bulbs were responsible for the Deancat (the lowest bridge deck, heaviest weight cat I have ever seen - I mean it has a bathtub FFS) making 9 knots cruising speed whilst my old Snowgoose 35 at under half the weight would only do 6...

I was not convinced

[geoffr]

Originally Posted by Snowgoose35

According to one South African sailor I met those sacrificial bulbs were responsible for the Deancat (the lowest bridge deck, heaviest weight cat I have ever seen - I mean it has a bathtub FFS) making 9 knots cruising speed whilst my old Snowgoose 35 at under half the weight would only do 6...

I was not convinced

Not convinced with good reason I think:

We ran into some cadets from the Annapolis navy school and were told that at the speeds a Prout would move at (vs a tanker at 20 knots) the bulbs won't create the required change in the bow wave to help.

We have since taken them off... and gald we did as they were water logged!

[atoll]

Originally Posted by Snowgoose35

According to one South African sailor I met those sacrificial bulbs were responsible for the Deancat (the lowest bridge deck, heaviest weight cat I have ever seen - I mean it has a bathtub FFS) making 9 knots cruising speed whilst my old Snowgoose 35 at under half the weight would only do 6...

I was not convinced

most likely reason the bulbs were put on by dean cats , IMO ,is when the model was first launched the trim was wrong from it being slightly too heavy in the bow.

the extra 90-100 kgs bouyancy displacement would have rectified the problem to some extent,and helped with pitching/hobbyhorsing from the boat being too heavy in the bows.

[Buzzman]

**Allegedly** this is why Lock Crowther had small bulbs fitted to the Spindrift catamaran series also - additional buoyancy in the bows to aid lift after burying the bow(s).
Or so my mate, a Spindrift owner, reckons....

[atoll]

Originally Posted by Buzzman

**Allegedly** this is why Lock Crowther had small bulbs fitted to the Spindrift catamaran series also - additional buoyancy in the bows to aid lift after burying the bow(s).
Or so my mate, a Spindrift owner, reckons....

i rest my case,councillor....every thing else is sales talk

[smj]

I remember a late 80's Snowgoose that had bow bulbs added to lessen pitching problems. Don't know if it helped or not.


Sent from my iPhone using Cruisers Sailing Forum

[Snowgoose35]

All the evidence about speed etc proves bulbs only makes a difference over about 18 knots (IIRC) hence they adorn large ships who make constant "high" speeds.

I have always thought the Deans had them for buoyancy - the boats are just way too heavy.

[atoll]

Originally Posted by smj

I remember a late 80's Snowgoose that had bow bulbs added to lessen pitching problems. Don't know if it helped or not.


Sent from my iPhone using Cruisers Sailing Forum

i would think that it would help to some extent by creating some lateral resistance from the added surface area and bouyancy.

however,for instance, getting rid of the dinghy hanging off the back on davits,the 2 massive anchors and 100 m of chain in the bow.then concentrating as much load in the middle would probably be a better solution

[atoll]

i finished the battening to support the ceiling head liners and insulation panels in all but the aft cabins.
the boat feels a lot smaller with 1" of insulation throughout
though still 6ft plus head room in all the main accomodation areas.

laminated ceiling panels nearly finished for the saloon and fwd cabins.
currently making up molds for moulding up trims for all the deck hatches.

snow in the yard!,spring must be on its way,it never snows in cornwall

ordered all my batterys ,500w of solar ,charge controllers etc should arrive next week.
happy days

[Excalibur5]

What flavor of batteries and where do you intend to mount the solar? Are you using MPPT or PWM charge controllers?

[Excalibur5]

Oh and one other thing, be sure you have a vapor tight seal (caulking or similar) between the ceiling hatch frames and the side of your insulation. If this is not tight in cold weather, you can get some water under the insulation and mold.

Looks like you did a beautiful job sealing the rest of the insulation though!

[atoll]

Originally Posted by Excalibur5

Oh and one other thing, be sure you have a vapor tight seal (caulking or similar) between the ceiling hatch frames and the side of your insulation. If this is not tight in cold weather, you can get some water under the insulation and mold.

Looks like you did a beautiful job sealing the rest of the insulation though!

thanks for the tip,will do.
as i'm still making up the mouldings for the hatches, i had to leave a bit of clearance around them so will seal up properly there when i fit them.

the 2 new panels are 32 v 255w poly 18 kg each and will go either side on the cockpit roof,similar to yours.

batteries are 2 banks
engine and house in the engine compartment 2x 6v, T105,225Ah giving 12V (56 kg),for anchor windlass,fridge,lights,300w inverter and instuments.
with a 60A 240 v charger
12v battery monitor

with probably 200-300w of solar on a stern arch run in series to a mppt.

i have also run wiring for 2 panels either side of the main hatch on the coachroof if having a stern arch is not possible due to weight or if i want more solar.

the other bank is 2x 12v 110ah agm in series giving 24v mounted just behind the mast step (52 kg)

this is charged by the 510w of solar via a high efficiency programable pwm charger and battery monitor.
this in turn charges the 12v bank with a 12.5 amp 24v-12v battery to battery charger(with 2nd charger as backup).

it will also run a 24v 4500w inverter,and one of the bow windlasses that is 24v for intermittant use(these i bought for my other boat but never used)

i thought this would be the best solution to eliminating a redundant engine start/house battery system, (and will act as a back up for an engine start battery if needed.)
plus with the battery to battery charger it will trickle charge 24/7 the 12v bank for house loads overnight.

current power needs are probably only 300-400w on the 12v system
so the 24v system should give me 75- 100% reserve power.
plus give me the option of a 24v watermaker in the future if needed.
i also have a 12v wind generator,that i might fit.

[atoll]

i found this for sale on ebay,brand new,no use to me but might be useful to anyone who needs to replace or install a sillette catamaran drive,it is the mk2 version,1:1 ratio.100cm.long for use with a gearbox,as fitted on many prouts and gemini's
£1850,a steal as new units are now about £5k

https://www.ebay.co.uk/itm/Sillette-...19.m1438.l2649

[atoll]

2 x 225Ah T105's fitted in the engine room,apart from bolting the cables on,which after being assured by the supplier that they had 8mm lugs,discovered they are 5/16 but fortunatly had some in the workshop,so will get the 12v system up and running again in the morning.

the new 24v system has been up and running the last few days,with the batteries at 100% SOC after using the inverter all day to fit the headliners,very happy not to have to lug the generator out ,and start it up everytime i need to use a power tool!

i might have miscalculated the amount of Ah i will need for day to day living using the 24v system as a trickle charger overnight for the 12v system,so might get another 2x 100AH agm batteries,that will fit next to the inverter in the outer locker.

i saw 9.5amps charge current initially untill the batteries became fully charged,then pretty much stayed in float,charging between 0.7a and 2.5a when i used the inverter,then quickly returned to 100% SOC.

using the figures quoted by rolls and lifeline for AGM batteries.
AGM Charging : Technical Support Desk
i set the charge parameters at 13.3v/26.6v for float,which i might increase slightly once i see more morning figures on resting battery voltage.
i set bulk/absortion at 14.8v/29.6v
and boost/equalisation at 14.9/29.8v
with a maximum charge current of aprox 12-14amps in full sun if demanded in bulk mode with battery temperature compensation on charge voltage.

so far so good
inverter is 1200w,not 4500w as i quoted in the previous post