Propulsion, Piracy and Progressive Design

Hi Ted,
Been reading your articles with great interest and thought I’d drop a couple of suggestions for new articles:


1. Engine placement, some thoughts are well explained here:
http://www.liveantares.com/7Questions.htm#propulsion however one that remains is what about fumes, engine odors and noise from midship placement?

TC:

When ex-marine mechanics wax nostalgic, their reveries are of the walk-in engine rooms they could amble around in, patting the warm flanks of heavy horsepower. Competing nightmares of contortion and claustrophobia return them to the reality of small boat engine installations. If by chance one of these lads finds himself responsible for new designs, altruism may lead him to favour the next generation of marine mechanics with something closer to the former rather than latter experience.  I suppose I was predisposed to put the engines where I could get at them.

engine room

The compartments ahead of the engines were intentionally kept open to provide a place to stand, almost walk-in engine rooms.

These days, engine placement seems to be subject to of a number of priorities related more to marketing and inexpensive installation than to practicality. In the case of the Antares 44, the goal of creating an ocean cruising vessel for individual owners trumped any compromises (ed. there is that word again) related to charter vessel sales. This required that propulsion efficiency, accessibility and robust installation were the watchwords, hence the most practical engine installation we could work out.  We also wanted the props in the most effective location; low down and ahead of the rudders, with shaft exit at the keel/fairbody juncture and minimal shaft angle.

Though the possibility of fumes and odours should not be discounted, the modern diesel engines we deal with are not prone to leaks of any sort.  The presumption is that the engine spaces in small boats will be contiguous with the accommodations regardless of the boat style and manufacturers construct accordingly, there is zero tolerance for fuel, exhaust or crankcase fume leakage.  This was not historically the case and some older diesels were famously dirty.  Fuel line fittings could be subject to seepage and the standards and technologies associated with the ancillary equipment were variable.  These days if your engine’s presence is revealed by an odour, there is something that needs your attention.  The nice thing about the central engine placement; you actually know if something is wrong (sniff?) and can get at it to remedy the situation.

Any time the engine is running, it is ingesting a substantial amount of air which makes the engine space a mildly negative pressure zone.  Even with adequate intake ventilation this will always be the case.  As a result, some small amount of air is always drawn into the engine spaces from the accommodations; fumes or heated air thus being burned and sent out the exhaust pipe along with any drifting cat hair etc.  The Antares 44 is equipped with oversized exhaust blowers in the engine space ventilation ducts that may be turned on when the engines are stopped. The heat of the engines will thus be dissipated without warming the accommodations.  Any odours associated with the engine or bilges are also exhausted while fresh air is drawn in, again partly from the accommodations.

Noise will be unavoidable regardless of where the engines are located.  The perception is subjective but less is always appreciated so acoustic insulation is always in order.  If serious attention is given to that installation, it is quite effective as evidenced by modern gen set enclosures.  The central engine location with shaft drive and its associated propeller noise will theoretically be inherently more acoustically problematic than tail mounted saildrives for example, but the speculative lower sound levels do not justify the associated disadvantages in our estimation.

2. Piracy, and this goes for most catamaran designs, one common form of piracy (maybe more burglary) is boarding ships (common on monhulls through their dingy), not really an issue here but… As nice as the swimming stairs are, it does kind of seem as putting the red carpet out.

TC

Designing for the unlikely contingency of piracy at the sacrifice of ready and safe daily access to the water and docks would be tantamount to shooting yourself in the foot (both feet for a catamaran) so that someone couldn’t steal your shoes.

Maybe a grander answer to piracy is to address the social/geographic motivations for the undertaking rather than initiate a new class of porcupine cruising yachts. If this is too liberal an answer, you could try sprinkling carpet tacks over the deck at night to discourage the native population from setting their un-shod and unwelcome feeties on board, (idea stolen from Joshua Slocum). Just don’t forget to sweep them up before rushing on deck in response to the anchor drag alarm.

Joshua Slocum

Joshua Slocum

3. On the topic of burglary, when I leave my home I lock my house down. Most designs seem to have a complete trust in humankind and just leave everything wide open. What about leaving my ship (house) for a 3 weeks hike? Does it come down to asking others to babysit it?

TC

The boater’s pride may be served by an enhanced demonstration that he is one of the ‘haves’, but presumably he must then accept some ancillary attention from the ‘have-nots’?

I believe for many years the general boat building practice has been to provide deck hatches and doors with the means to prevent outside access. Those who choose to leave everything wide open are perhaps satisfying their own sensibilities. In any case, most marinas deploy some kind of defensive perimeter against the unwashed masses, the gated community is thus made ubiquitous.

marina guard

Friendly Mauritius Marina – Ambiguously directed measures may give one the sense of having already been caught embezzling?

I concede that I may be an idealist and naïve, but I like to think that the purpose of travelling is to have some interaction with the local geography (human and physical). Displaying a notion of security that is overtly offensive doesn’t seem very constructive to that end.

ostentatious display

Avoiding ostentatious displays offers some security

Some kind of local babysitting for your cream puff will most likely be available for the duration of your three week hike.

watch your yacht

Locals extorting a “watch your yacht?” ad hoc security service

I think engaging with the local enterprising kids offering ‘protection’ may be rewarding, at least the disparity between the haves and have-nots could thus be somewhat alleviated after three weeks of payments.

Seriously though folks, here is some firsthand experience with related stuff;

4. Another question that begs after reading how harsh you can be on other designers :) is what do you admire in other designs, is there anything you would do different design wise now with the Antares 44 or do you already incorporate those lessons?

Rather than ‘harsh on other designers’ I would suggest that the criticism has been applied to resultant product, which is an amalgam of marketing, purchaser indiscretion, building practice, costs, etc., the results of which may be equally dismaying to the designated designer as they are to you or me.

The unfortunate truth is that you only learn from your mistakes. When something goes well, it is a non-issue; a miss being a miss. Mistakes however dismay and plague one at night, preventing sound sleep (reveries of walk-in engine rooms). I have made a disproportionate number of mistakes in various fields of endeavour, so I know whereof I speak.

Appreciating the mistakes more than the successes leads to a level of self-criticism that hopefully translates into more rigorous design work. The same level of criticism is unavoidable when looking at the work of others though this may appear as being ‘harsh’.

There seems to be a remarkable degree of reverence for dumbass design in all products, I don’t confine my disappointment to boats.

tub

I guess there is a usable shower in the basement

I hope that by writing (possibly amusing) critiques I will generate a more critical eye in the prospective boat owner, regardless of what he acquires.

To the very limited extent that the design for a rationalized product may be considered an ‘artistic’ statement, intentionally emulating the efforts of others would be anathema. However, though sensitivity to line and form could possibly be a genetic disposition, the exposure to example is a certainty, and in this regard I may be fairly regarded as a copyist.

ship

Surviving half of famous 19th century catamaran

Whatever is ‘good’ and ‘attractive’, though subjective, will hopefully be automatically manifest in whatever I come up with. Everything is built on what has come before.

The 44 design is over ten years old yet still enjoys an increasing level of acceptance. The rationale that went in to the design still stands. The peculiarly limited number and scope of the readily identifiable initial shortcomings were rectified a long time ago.  There are some non-critical things I would possibly do differently today, not because they are mistakes to be corrected but rather because the underlying parameters have perhaps shifted, (do you like black more than white? or vice versa?). The changes would very likely meet with rejection equal to their acceptance so the wisdom is suspect. There have been changes over the years but primarily with equipment and hardware. The owner of hull #1 wouldn’t lose his way in the dark on hull #41.

5. Basically relates to 4 but do you incorporate feedback such as the modifications made by the Seaman’s Elixer crew in new builds? The cockpit does seem to evolve.

Customisation by individual owners seldom translates into a generally accepted ‘improvement’.  I like the idea of ‘ownership’ however and think that you should experiment (fool around) with your boat if you enjoy that sort of thing. When something proves out, is widely accepted as attractive, and may be adopted by the builder without undue liability, it may well show up in the new boat specs.

The cockpit in fact has not changed in any significant way other than the additions to the helm seat arrangement and the quality of the upholstery.  The evolution has been primarily from the utilitarian and toward the comfortable.  This reflects the general perception of what is desirable in a boat that will also act as a home.

Most design feedback is subjective and frequently countered by a non-apparent engineering rationale or an opposing opinion; but marketing is the craft of responding successfully to feedback in general and I think Antares does that rather well.

6. With regards to the cockpit, for your next build did you consider creating a little curve in the instrument panel above the compass in order to be able to move the bottom left and right instruments below the compass. Sort of like how it is done in cars. This would make the already awesome looking helm station even more aesthetic.

The flat real estate at the 44’s helm station is more expensive than Monte Carlo’s at $47,500.00 sq./M!

cheap

Cheap

valuable

Valuable

The ever changing nature of the electrical and electronic equipment that occupies the helm real estate precludes any curvaceous landscaping.  The cockpit mouldings were designed back in 2000 to accommodate any likely advancement on the prevailing displays.  Almost immediately Raymarine, Furuno. Et.al. taxed the situation with new product (‘bigger and better’).  It was fortunate that we were able to shift the engine instruments and other pedestrian stuff up onto the (flat) bulkhead without much trouble.

FRP boats tend to be around for a long time and designing automotive type sculpted dashboards is very short sighted.  The powerboat market seems to accept this readily enough and that perhaps betrays some design criteria that’s shallower than we are obliged to consider.  The general sailboat market is severely limited in display mounting by the ubiquitous pedestal and contingent cockpit obstruction.

We were fortunate to have the means, provided by the nature of the boat, to take advantage of the developments in electronic navigation displays as they have come along.

I understand your idea of raising the compass into a ‘bubble’ on the deckhouse top edge but this is a structural zone of some substance and thickness (1”+).  In practical terms, such a change would entail a larger lump than you would expect and require a modification to the major deck mould.  That cost added to the cost of re-tooling the panel would seriously handicap any cost/benefit analysis.  Additionally, I have intentionally avoided any obstructions to the lines of visibility for the seated helmsman.  This consideration also precluded top mounting a compass in the same space envelope.

It is always tempting to perhaps cheat the helm console spaces with some fancy geometry, but I won’t do it.

We must continue to rely on the helmsperson to provide the curves.

TC

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