Need for speed, 19th Century style

[charmc]

There is a well researched and excellently written article by Donald Blount in the new issue of Professional Boatbuilder. The article describes the remarkable advances in speed of steam engine powered vessels in the 2nd half of the 19th Century. Parson's revolutionary turbine powered Turbinia hit 34.5 knots in 1897, but Thornycroft built a 40' steam engine powered boat that reached nearly twice hull speed in 1863. 10 years later, another small (45') Thornycroft steam engine launch exceeded 21 mph. From then until the turn of the century, a variety of yachts, launches, and (of course) military vessels reached speeds between 30-40 mph and 2-3.5 times hull speed with reciprocating steam engine power.

The digital edition hasn't been posted yet, but Blount and his associates located some unique photos of some early vessels running at high speeds. One series of photos illustrates the challenges of designing hulls for such high speeds: a boat is shown submarining as it accelerates to maximum speed. There are 2 early diagrams showing experimental add ons to modify round bottom hulls with hard chines.

Eventually it will be available for viewing or purchase on the magazine's website. I congratulate all those involved and recommend the article to anyone interested in early powerboat history.

[Fanie]

Interesting Charlie, now if we could just get hydrofusion to work as we want it to, the very water your boat sits on could create those old things over again but with some new technologies, better speed, cheaper and more healthy.

[waterman]

Something to consider in that article: at that time planing craft were unheard of. At the time, it was believed that it was impossible to exceed hull speed. Exceeding hull speed or achieving 2 times the hull speed was breaking new ground.

[PAR]

They knew they could exceed the theoretical limits imposed by LWL, but they weren't sure how much. They had both light weight "skimming dishes" (sand baggers) and catamarans, that easily trounced the displacement speeds of similar length craft. Not to mention dozens of different types of small craft like sharpies and scows.

Several designs dating back to the mid 1700's clearly show bottoms developed for planning craft (intended to generate substantial lift underway). These were first pulled down canals, latter in the early 19th century, steam power. The generally and seemingly universally accepted hull shape was the slightly inclined, straight rabbit bottom, through the late 1800's, where Herreshoff tried a "fat stern" hull form (wide transom to prevent squatting), which after tested, he didn't like (too much drag at lower speeds) as much as the inclined bottom he was most familiar with. Others took up the low transom designs and by the turn of the 20th century, when gas engines begin to over power steam, mid twenties was quite common, with 30's for exceptionally powered vessels.

[Meanz Beanz]

Now I want to see that Charlie.

[masalai]

But you wouldn't really consider it an option to replace any existing marine vessel except for "nostalgia" or personal amusement...

[charmc]

Originally Posted by masalai

But you wouldn't really consider it an option to replace any existing marine vessel except for "nostalgia" or personal amusement...

No, my interest in the article is in the great advances in speed and in engine design in an earlier era. My impression of a steam engine powerplant, from having been in the engine rooms of USS Maine, several paddle wheel riverboats, and a few old factories with stationary Sterling engines, was a huge, heavy, iron construction with coal boiler that went pocketa pocketa pocketa. Hard to imagine African Queen doing 30 knots, with Humphrey Bogart running around tying rags around the steam piping.

These boats were in a whole different world. The article widened my horizons, reminding me that powerboat speed didn't originate with the internal combustion engine.

[masalai]

True Charlie,
Nothing like the "romance" in the old vessels... Go and admire the workmanship, elegance and beauty... A bonus is if it is in working order and for a small fee go for a ride!!!

[PAR]

From a fuel useage view point many of these early powercraft were far more efficent. They had HP to engine weight ratios in the hundreds of pounds per range, meaning they had to have very efficent hull shapes. 25 HP may have required a 2,500 pound engine, not to mention the coal stores to fuel it. Gas and "heavy oil" engines reduced this quite a bit, but it took the better part of a half a century to do so.

By the earily 1960's a 30 HP outboard was developing a single HP per 5 pounds of engine and fuel, so efficent shapes weren't required and fat butted tubs became the fashion, which is still with us today. This will not likely change until, fuel costs rise considerably more.

[masalai]

OK Par I am with you now, US$200 a barrel by Xmas.... That should get things going in a better (more fuel efficient direction) quickly...

[PAR]

I'm hoping the worry, over certain reports of oil futures on the commodities market in the next 5 years will blow out soon, so the price can stabilize, maybe around 150 a barrel. The yachting industry will be the last to accept new tooling and molds, so don't hold your breath for narrow, efficient boats in the next few years. Designers and builders have weathered similar "black" years or slow trends in the past, but will likely ride it out and hope the can eventually liquidate their inventory. It will weed out the weak and small, non-divested manufactures, but most have their hands in quite a few different operations.

I'm personally a fan of some of these old, narrow and efficient hull forms and would love to see a come back. With my luck they'll find a huge, previously unknown oil reserve under Washington DC, place rigs on the lawn of the White House and we'll be living in happy, low cost fuel land again.

[safewalrus]

But I doubt it PAR!!

Fuel is changing and so is the capacity to stow it, or use it! Now nuclear is rather good - nuclear subs tend to be steam engines!! Not because steam engines are good but because the boiler end is so damn efficient anything else is pointless! (in a nutshell - I'm sure you can put that in a more technical way that will use about twenty six pages - never use one page were ten will do!)

No efficiency of hull shape should be the norm, wither it be because of weather or the requiremnt for speed! Then it's the size ans shape of the power plant! lets get away from these short fat little boats and get back to long lean beautiful machines! Either power or sail!!

[bear]

How 'bout one of these? http://www.sky-net.org.uk/kelvin/launches/index.html

[DanishBagger]

Originally Posted by safewalrus

But I doubt it PAR!!

Fuel is changing and so is the capacity to stow it, or use it! Now nuclear is rather good - nuclear subs tend to be steam engines!! Not because steam engines are good but because the boiler end is so damn efficient anything else is pointless! (in a nutshell - I'm sure you can put that in a more technical way that will use about twenty six pages - never use one page were ten will do!)

Come now - I have never seen any posts from the hand of PAR that were longwinded. Some have been long, but only to explain something - in full detail - to numbnuts like you and me.

[PAR]

I don't expect real change to affect the industry, until fuel prices in this country reach the $7 - $8 per gallon range, which means the world will be suffering through $300 a barrel pricing.