I'm going to reprint the replies I got from various other email
groups in response to the subject of connected/independant sidewheel
paddler drives.
_____________________________________________________________________
From: "B. G. Dixon-Ward" <bdixonw@o...>
Date: Sun May 20, 2001 4:04 pm
Subject: Re: [Modelships] Passenger Side Wheelers
I don't know the position regarding the regulations on this, but it
does seem logical.
The mechanical arm of the couple represented by the distance between
the paddles of a side wheeler would be relatively large, resulting in
there being a possibility of a significant effect on transverse
stability if the paddles are operated in opposite directions. This,
in itself, may not be an insurmountable problem, but if it is combined
with the well known passenger ship problem of the effect on stability
of a large number of passengers rushing from one side of a ship to
another, there could be a real risk of an unnaceptable effect on
stability.
Paddle tugs, of course, don't have the moving weight problem when
manouvering, and in any case, their hull form can be adapted to
counter the problem of counter rotating paddles.. The effect on long
distance fuel consumption resulting from the modified hull form would
not be a problem in a harbour tug.
I have a very vague memory of a paddle excursion steamer in the Thames
estuary being involved in a major disaster around 1890s 1900s. This
may have some association with relevant regulations.
======================================================================
From: "Alistair Deayton" <Alistair@d...>
Date: Sun May 20, 2001 1:37 pm
Subject: Re: [Waverley] Sidewheeler drive shaft
"That (all British passenger side paddlers had a single drive shaft
permanently connecting the two wheels) was the standard arrangement
for paddle steamers in the UK and Europe, apart from some tugs. In
the USA, especially in the Mississippi and tributaries, they had
separate engines for each paddle on side-wheelers."
======================================================================
From: Jamie Christie <jamie@b...>
Date: Sun May 20, 2001 12:46 pm
Subject: Re: [Waverley] Sidewheeler drive shaft
Royal Navy Sidewheel Tugs had independant drive shafts which could be
connected during ocean voyages.
"Many could as that was the key to their wonderful manoeuvrability. I
believe Waverley does have two independently driven paddles, or am I
thinking of another paddler?"
=====================================================================
From: jnewth@j...
Date: Mon May 21, 2001 8:05 am
Subject: Re: [Scotships] Sidewheeler drive shafts
As far as I can ascertain the practice of fitting twin, disconnecting
engines driving twin independently rotating paddlewheels began in the
1880's, allowing greatly improved manoeuvrability, especially for
tugs. In the days of steam tugs, side-lever engines were commonly
fitted, and the design of this particular kind of machinery permitted
two similar engines to be installed side by side. Normal practice
when free-running was to link the shafts together, this being done
with a spline-type clutch. For towage in narrow channels, the clutch
would be disengaged, allowing the tugmaster to use the paddles to
assist in steering, giving very rapid response.
As most pleasure steamers were built to sail from point to point,
this manoeuvrability was not as important as the ability to steer in
a (relatively) straight line, so paddle shafts were generally
continuous. I believe that the Board of Trade (later Department of
Trade/Trade and Industry/Transport, Maritime Safety Agency and now
Martime and Coastguard Agency) had rulings about this, probably
citing lateral steerage ability as the reason for not allowing split
drive, though I can't find any documented evidence of this within my
own collection of books and other archives at the moment.
Incidentally, even the paddle motor vessel TALISMAN, built in 1935
for the London and North Eastern Railway, had a single drive shaft.
Regards, John
======================================================================
From: Geoffrey.Hamer@b...
Date: Mon May 21, 2001 8:43 am
Subject: Re: [Scotships] Sidewheeler drive shafts
I think the ferry CLEDDAU QUEEN, built in 1956 for Pembrokeshire
County Council, had independently-powered wheels. She was the last
paddle steamer built in this country, but was a small, slow ship.
Most excursion paddle steamers were powerful ships for their size,
and I'd imagine independent wheels would be quite impractical if not
dangerous.
END OF MESSAGES
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
So, after these few responses from other email groups, I was struck
by the paucity of DEFINITIVE information...seems a bit like some
"guessing" going on here (the bain of model researchers!)
I think Ken's answer from our own Paddlducks forum seems logical and
should serve to guide our inquiries.
--- In Paddleducks@y..., "Paddlewheels" <info@p...> wrote:
> Hi ,
> You are quite correct in that British side wheelers were prohibited
> by law to have independant drive to each wheel. You are also correct
> in that some had the capability to disconect one wheel for
> manuvering for docking.This was acomplished by use of dog clutches
> to each half of the split shaft,I believe though i am not certain
> that the disconected wheel could not be driven in reverse direction.
I believe Ken is referring to Passenger vessels here. Add to this
that we KNOW the Royal Navy/RMAS "Director" class Paddle tug of the
1950's DEFINITELY had independently reversing wheels which could
be connected for open sea navigation.
We have to consider WHAT are the definitions of "connected paddle
shafts" and "independant shafts" ? Obviously "SOMETHING about
passenger sidewheel paddles" was governed by laws in the UK.. the
question is WHAT! ..and did the steamship companies find a way of
circumventing the law(s) which they might well have attempted if it
meant increased revenues in any way. As Ken seems to suggest, (some)
passenger sidewheelers could disconnect their shafts and control
their wheels independantly for docking. Did this mean the law stated
that shafts MUST be locked for open sea navigation (?) and, if so what
is THAT definition? Maybe the law permitted "unlocking" of shafts but
did this go so far as to permit the reversing of a paddle?
And the BIG QUESTION....Were sidepaddlers in other countries (and
particularly the US) governed by any such laws? It may well be that
Canada (at the time still a Dominion of Britain)would have been
governed by British Maritime laws.
FACT: Independant REVERSING paddle provide incredible maneuverability
... BUT in open sea they have been seen to be dangerous and have
contributed to some disasters.
FACT: At some time there was a law(s) governing the "use" (or maybe
even installation) of independant side wheel drives in passenger
carrying veesels in the UK.
FACT: One class of Royal Navy Tug was equipped with compeletely
independant reversing wheels.
It looks like paddle shafts in prototype sidewheelers MAY have been
as follows
1) Permanently connected
2) Connected but able to be "split" through clutch(es).
3) Independant but able to be connected.
4) Permanently independant (
) doubtful but who knows!!
MODELING: (My own take on all this) RESEARCH EACH INDIVIDUAL VESSEL
you are modeling. Be "guided" by the existence of one or two engines.
In models, independent reversing side wheels are fun to operate,
great to watch and give a tremendous advantage in steering
competitions (I CHALLENGE ANY SCREW PROP VESSEL TO BEAT MY "DIRECTOR"
Class sidewheeler which I can literally maneuver and stop within 1/8"
of obstacles as though it was "on tracks"). I suspect I may
eventually be banned from steering competitions as having an unfair
advantage.
People have already asked me to verify that the prototype vessel of
my model had independant paddles ! Beginning to get my drift of what I
may be faced with in steering competitions? ...but this is really the
ONLY area of trouble I see. The first time out, you'll draw oohs and
ahhs and people will be impressed with the incredible control you have
over your vessel with independant drives but after a few times of you
winning, the questions (and bleating) will start!!
Other than that..seems it's all a personal choice. However, unless
someone can show me a simple clutch mechanism for independantly
stopping/reversing the wheels with just ONE engine, I'm still
inclined towards two separate engines (even if they didnt exist in
the protoype). I originally ran my boat with one engine driving both
paddles and rudder steering. She looked very pretty in the graceful
turns, but docking was to say the least "challenging" and I'd often
end up losing way and going sideways approaching a bow first docking.
(she also had an unmistakable affinity to "waddling", something you
have to be careful about with connected paddlewheels, specially if
your balance/C of G is wrong).
When I researched the mechanicals of the prototype, I realized
WHY they were so maneuverable. These tugs were equipped with two
massive diesel electric engines with all the commands to the
paddlewheels directly controlled electrically from the bridge. I
wanted to replicate this in the model.
Each engine in my "Director" has fully independant reversing and
speed control which is activated by "commands" sent out by the rudder
position to "simulate" the controls of the prototype..and ONLY in 2
CHANNELS!.
However the "real" vessels had their shafts "locked" for open sea
navigation and I wanted to replicate this too. By moving the "helm"
hard over, the steering servo horn strikes a push on/push off micro
switch to cut out the "independant drive" electrical circuit and
defaults it to a simple circuit which provides the same power and
direction to each wheel (simulating "locking" the shafts) so steering
is then purely with the rudder. THIS makes the controls prototypically
correct (and my research comes from unimpeachable sources!)
So there we have it... I remind you all that "model" research is
fraught with danger of "guessing", speculation and the "whisper
chain" syndrome. Conclusions MUST be backed up with FACT. As one
one the best researchers in Model Railways once told me "people
remember what they WANT to hear". ACCURATE research can be part of the
fun of building models, but.....
.....on the other hand, life is sometimes too short and if you're not
worried by all this..JUST HAVE FUN WITH IT..and build whatever YOU
WANT and whatever is easiest for you to build to OPERATE. Spend your
time on the water rather than poring through books, and in this way
you'll never have to "explain" what you've built. Somehow, I'm trying
to achieve a happy medium.
These are my OWN observations... the book is still open on this
subject of sidewheeler shafts which, for me, is really just another
illustration of the phrase "the more I learn, the less I know!"
Keep paddlin' !..it's only upstream ONE WAY!
PJ
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