Masthead31_Sept2014.pub - page 6

The Masthead
First To Fly
Continued
craf t may not reach full planing untill an S/L of 3.2. By the same token, an ultra-narrow round bilge
boat l ike
Ursula,
achieves a substantial portion of her speed by wave pierc i ng rather than by sk im-
mi ng or p l ani ng . I t wou l dn ’t be ful ly accurate to call her a pl ani ng boat , even though she cer ta i nl y
does experience some Ramus effec t at h igh speed . (Reverend Ramus wasn’t forgotten. Magazi ne
ar ti cles and books of the early 1900s somet imes referred to pl aning as “the Ramus effec t.”)
Turbo !?
While
Ur sula
was one of the last of the ul t ra-s lender racers, the mos t famous c raft of th is type was
Sir Charles Parsons’s
Turbin ia.
Launched in early 1896,
Turb in i a
was 103 feet 9 i nches overal l, an
amazi ng l y nar row 9-foot beam, and d isp laced 44.5 tons. She di d 34.5 knot s, powered by three axi a l
- f low steam- turb ines de li veri ng a tota l of 2,100 horsepower. Her engi nes turned three prop shaf ts ,
each f i tted wi th three props—st range . The boat i ni ti al ly d idn ’t make expec ted speed with a s i ngle
propel ler due to cavitat ion prob lems . The unusual prope ller arrangement was to get suff icient blade
area with limited diameter.
(The turbi ne eng i ne was the
f i rst of its k i nd i n a boat ,
hence her name ). Speed-
length ratio works out to 3.5
( supposedly p lan i ng , but not
real ly so for this ultra-narrow
round-bi lge hul l) . It did , how-
ever , make
Turb in i a
the fast -
es t boat i n the world .
Hi gh -Speed Hi j i nks
I n fact , Sir Charles took her
(uninvited) to the naval sh ip
parade at Queen Vic tori a ’s
Di amond Jub ilee and caused
quite a ruckus . He zi pped i n,
around , and pas t every s i ng l e
boat , f rom the l arges t battle -
wagons to the fleetest
escor ts—mos t ungentleman ly .
Several of the fast escorts
even t r ied to chase
Turbinia
down to head her off (one
coul dn’t al low proper deco-
rum to be ignored , af ter a ll ),
Sept. 2014 Page 6
Turbinia,
on display at the Newcastle Discovery Museum, showing her
unique triple-shaft, triple-propeller arrangement.
1,2,3,4,5 7,8,9,10,11,12,13,14,15,16,...24
Powered by FlippingBook