TP52 as a cruiser....?

[flaming]

Just about ready to splash now...

J-Bird Sailing

And they've entered the Sydney-Hobart in the Doublehanded class. Which is, er... punchy!

Part of the rationale is that they will be the first electric powered yacht ever to enter, and they want to jump through all the hoops to prove that it can be done and to make it easier for future electric powered yachts.

This project really is something else....

 

[dunedin]

Just about ready to splash now...

J-Bird Sailing

And they've entered the Sydney-Hobart in the Doublehanded class. Which is, er... punchy!

Part of the rationale is that they will be the first electric powered yacht ever to enter, and they want to jump through all the hoops to prove that it can be done and to make it easier for future electric powered yachts.

This project really is something else....

Can you really just launch an untested “new” boat and go in the Hobart? Are there no pre-qualifying requirements in terms of boat races/mileage before heading down to Hobart?

The “first electric powered” is very much a moot point on a race sailing yacht. Clearly it is “sail powered”.
And most serious race boats have relatively small engine, and carry the minimum of fuel permitted in the rules for the event - hence tiny range in race trim. As such entirely trivial to fit an electric drive with minimal power and range, and be much lighter than a diesel Installation. No high tech innovation needed there.

Ironically, it seems that some of the bigger race boats now need generators running non stop whilst sailing, to power all the winches, hydraulics - and now foils. Boat test in Yachting World, I think, where tester comp,aired about the constant generator noise and relief when finally closed down.

 

[Daydream believer]

One might have a 50 ft boat, but does one have to have sails for a 50 ft boat.
For instance, they could get a smaller main. The inventory probably includes a smaller set of foresails
One does not have to blast around the ocean all the time, just because they can.
That being said !!!!!!!!!! ?

 

[flaming]

Can you really just launch an untested “new” boat and go in the Hobart? Are there no pre-qualifying requirements in terms of boat races/mileage before heading down to Hobart?

Yes, they need to do qualifiers.

The “first electric powered” is very much a lot point on a race sailing yacht. Clearly it is “sail powered”.
And most serious race boats have relatively small engine, and carry the minimum of fuel permitted in the rules for the event - hence tiny range in race trim. As such entirely trivial to fit an electric drive with minimal power and range, and be much lighter than a diesel Installation. No high tech innovation needed there.

From the regs.
An engine which provides a minimum speed in knots of (1.8 x √LWL in metres).
At the start a boat with an electric engine shall carry sufficient capacity to meet electrical requirements for the duration of the race and to motor at the above minimum speed for at least 5 hours.

I make that speed roughly 7 knots for a TP52.
That means that the electric boat has to carry enough battery capacity on the Hobart to motor at a pretty high pace for 5 hours, on top of all the power that is necessary for the race. Which is a pretty high bar.... No electric only boat has ever done it before, and these guys are partly doing it specifically in order to be the test case.

 

[dunedin]

From the regs.
An engine which provides a minimum speed in knots of (1.8 x √LWL in metres).
At the start a boat with an electric engine shall carry sufficient capacity to meet electrical requirements for the duration of the race and to motor at the above minimum speed for at least 5 hours.

I make that speed roughly 7 knots for a TP52.
That means that the electric boat has to carry enough battery capacity on the Hobart to motor at a pretty high pace for 5 hours, on top of all the power that is necessary for the race. Which is a pretty high bar.... No electric only boat has ever done it before, and these guys are partly doing it specifically in order to be the test case.

As ever with electric, there is a yes and no there.
Regarding race battery demand, a TP52 under sail will normally be doing 8 knots or more - which makes hydrogeneration extremely effective. A Watt &Sea off the back easily does this for a fast cruiser on an ARC (but might get blown off the back of a TP52 surfing at 20 knots). A decent electric saildrive would work even better. So provided they are prepared to accept a little bit of hydro drag in race power no issue.

And suspect wouldn’t take much power to push at TP52 at 7 knots in flat water, flat calm, to meet the rules.1 horse can pull a 100 ton barge at low speed. Its when approaching hull speeds (or add real world wind and waves) that power demands up.
Is their tech spec somewhere out there in the detail ?
Not done the precise calculation but guess a 20kW drive would suffice, and only need around 10kw x 5 hours = 50kWh (probably quite a bit less if pushing the letter) to meet the rule? So nothing that can’t already buy over the counter as a production option for an Arcona, XY, Spirit etc.

 

[flaming]

As ever with electric, there is a yes and no there.
Regarding race battery demand, a TP52 under sail will normally be doing 8 knots or more - which makes hydrogeneration extremely effective. A Watt &Sea off the back easily does this for a fast cruiser on an ARC (but might get blown off the back of a TP52 surfing at 20 knots). A decent electric saildrive would work even better. So provided they are prepared to accept a little bit of hydro drag in race power no issue.

And suspect wouldn’t take much power to push at TP52 at 7 knots in flat water, flat calm, to meet the rules.1 horse can pull a 100 ton barge at low speed. Its when approaching hull speeds (or add real world wind and waves) that power demands up.
Is their tech spec somewhere out there in the detail ?
Not done the precise calculation but guess a 20kW drive would suffice, and only need around 10kw x 5 hours = 50kWh to meet the rule? So nothing that can’t already buy over the counter as a production option for an Arcona, XY, Spirit etc.

Oh I wasn't saying that it's not currently available as production items, after all fitting production items is exactly what they are doing. Just that although the rules have been written, this is the 1st attempt to actually enter a boat with an all electric power train, so getting signed off as approved to race will be a challenge, as they'll be the 1st to present a system and be asked to prove it meets the rules.

Happily they wrote a nice couple of articles about it....
Electric engines in yachts - Part 1
Electric engines in yachts - Part 2

 

[dunedin]

Oh I wasn't saying that it's not currently available as production items, after all fitting production items is exactly what they are doing. Just that although the rules have been written, this is the 1st attempt to actually enter a boat with an all electric power train, so getting signed off as approved to race will be a challenge, as they'll be the 1st to present a system and be asked to prove it meets the rules.

Happily they wrote a nice couple of articles about it....
Electric engines in yachts - Part 1
Electric engines in yachts - Part 2

Interesting, so my informed guesses without doing any new calculations seemed to be almost spot on:
- I thought they may have fitted a 20kW drive but actually slightly smaller at 15kW
- I estimated at under 10kW needed to drive at 7 knots in flat water - they calculated 7.5kW at 6.9 knots
- I estimated worst case for rules 50kWh battery, they estimated 37.5kW (sic - they missed the hours bit of the units in a few places)
However, only fitting 22.5kW (hours) battery pack - and saying they will advise later how filling the gap (presumably a fuel cell, rather than a diesel generator!)

So all looks fairly standard stuff, albeit done a bit more of the proper “maths” than some optimists.

One thing should take with a pinch of salt is their dismissal of the scientific conversion of 1kW to 1.34hp, saying electric drives it is a massively different 1kW “”equivalent to 3hp”. There is certainly an important point that electric drives have good low end torque.
BUT the “1kW Is equivalent to 3hp” is a marketing claim made for many small outboards, which typically works at low speeds - but not when the chips a down and need solid grunt when it turns out that science of 1.34 was actually, well, scientifically based. For example few 1kW outboards will get a tender up on the plane, even solo, but a clapped out old 2.5hp two stroke certainly will, with ease.

At the end of the day they have a circa 20hp motor replacing a 50hp diesel in a 52foot boat. Fine in the zero wind rules requirement, but perhaps less so if ever want to motor upwind into brisk breeze and waves (fortunately, if crew and rig working, the sails will do this better, but if have rig problems I wonder - or god forbid an MOB search in stormy southern ocean)

 

[Neeves]

Interesting, so my informed guesses without doing any new calculations seemed to be almost spot on:
- I thought they may have fitted a 20kW drive but actually slightly smaller at 15kW
- I estimated at under 10kW needed to drive at 7 knots in flat water - they calculated 7.5kW at 6.9 knots
- I estimated worst case for rules 50kWh battery, they estimated 37.5kW (sic - they missed the hours bit of the units in a few places)
However, only fitting 22.5kW (hours) battery pack - and saying they will advise later how filling the gap (presumably a fuel cell, rather than a diesel generator!)

So all looks fairly standard stuff, albeit done a bit more of the proper “maths” than some optimists.

One thing should take with a pinch of salt is their dismissal of the scientific conversion of 1kW to 1.34hp, saying electric drives it is a massively different 1kW “”equivalent to 3hp”. There is certainly an important point that electric drives have good low end torque.
BUT the “1kW Is equivalent to 3hp” is a marketing claim made for many small outboards, which typically works at low speeds - but not when the chips a down and need solid grunt when it turns out that science of 1.34 was actually, well, scientifically based. For example few 1kW outboards will get a tender up on the plane, even solo, but a clapped out old 2.5hp two stroke certainly will, with ease.

At the end of the day they have a circa 20hp motor replacing a 50hp diesel in a 52foot boat. Fine in the zero wind rules requirement, but perhaps less so if ever want to motor upwind into brisk breeze and waves (fortunately, if crew and rig working, the sails will do this better, but if have rig problems I wonder - or god forbid an MOB search in stormy southern ocean)

In the real world they will not need to motor into waves - they will turn round and go back. There are havens all along both coasts except for the bit in the middle - and then they motor with the wind (as once the motor is on - they are no longer racing). As Flaming says there are qualifiers (serious races), plural, they and the yacht are tested.

Jonathan

 

[flaming]

free as a bird

Seems that they regarded a lot of the SA thread as a bit negative on them, so wrote an article.

 

[Lightwave395]

Now that's my idea of a big cruising boat !