.... The inlet
pressure was 9psi -it's on all the web sites describing the
engineering -or are they wrong too?



Actually, they are. The design (according to Harlan & Wolff, who
should know) called for inlet to the turbine at ~ 11 psia. So, if you
grant them 9psi *a* then they're not far wrong.


Nav wrote:
Holy backpedal!!!!!!!!!!!!!

Way to go, Navsprit.

I'm right, you're stuck, so you call me names, holler that I'm
backpedalling, and go bwahaha.

I suggest you look at some slightly more sophisticated sources of info.
Not that you'd understand them, but at least you could try.

DSK

otnmbrd wrote:
This becomes an engineering question and I'm not an engineer.

Maybe, but you're a lot more of an engineer than Navvie.

... However,
considering the mass involved, I'd assume that the process for reversing
engines running at full sea speeds (even recips) would involve a good
deal more than just "throwing a lever" G

Oh yeah, it would take a bit of time and some applied skill at the
lever. You *could* just throw it into full reverse, but it would be
dangerous.

I assume commercial ships don't practice stop-and-lock or crashback
drills like a military ship does.

A stop-and-lock on a turbine plant takes a bit less skill, since all you
have to do is shut of steam on the ahead throttle and crack open the
astern throttle, then slowly open it further. Less things to break, too.
There's the risk of losing vacuum on the condenser (there are far fewer
stages in the reverse turbine) which I assume would not be the case for
a normal recip plant; but would be a potential hazard with the Titanic
because of diverting steam from the central turbine.

When the ship is going slower, it's a lot easier.


If the steam to the turbine was cut off and the central prop left to
freewheel, then the rudder would have lost some effectiveness... but
if the prop was engaged in reverse (which the Titanic's couldn't be
anyway) then it would be far worse.


Would require another turbine, but agreed.

Right... some people think you just hit the clutch and shift into "R"
apparently.




Well, if you're interested there is a lot of data to look at
http://www.titanicinquiry.org/
has both American and British inquiries and all the testimony.


G I've been through much of this in the past, so I've forgotten many
of the specifics, but remember there being many unanswered questions
since their knowledge base was relatively new at the time.

Didn't you used to participate in the alt.history.ocean-liners.titanic
newsgroup? That was an interesting bunch. I seem to recall you and a
couple of other old salts discussing the issue of bringing the
Californian alongside the Titanic.

Anyway, imho the Inquiries are the best primary source of info about the
collision & sinking.


At any rate, I'm a firm believer that the Titanic could have benefited
from today's technology on rudders, not only in size but in shape and
location (Hate a twin screw with single rudder).

Well, her hull was shaped much like the previous generation of sailing
ships. The aft sections would have to be shaped quite differently to
have twin rudders. But Olypmic & Titanic were goreous ships... they
looked like tremendous yachts to my eye.

Regards
Doug King

DSK wrote:


.... The inlet
pressure was 9psi -it's on all the web sites describing the
engineering -or are they wrong too?




Actually, they are. The design (according to Harlan & Wolff, who
should know) called for inlet to the turbine at ~ 11 psia. So, if you
grant them 9psi *a* then they're not far wrong.



Nav wrote:

Holy backpedal!!!!!!!!!!!!!


Way to go, Navsprit.

I'm right, you're stuck, so you call me names, holler that I'm
backpedalling, and go bwahaha.


I'd call it a backpedal when you now admit the inlet was not a vacuum
but at 9 or 11 psi !!! (The latter figure is not in any refs. I've seen.
Where did you get it?))!!!! Now tell us about the bypass valve that's
needed to connect the other engines to the condenser to bypass the
turbine steam path or do you still think the main engines can run with
their outlets closed?

Bwhahahahahah big time I'd say!

Cheers

DSK wrote:

otnmbrd wrote:

This becomes an engineering question and I'm not an engineer.


Maybe, but you're a lot more of an engineer than Navvie.

... However, considering the mass involved, I'd assume that the
process for reversing engines running at full sea speeds (even recips)
would involve a good deal more than just "throwing a lever" G


Oh yeah, it would take a bit of time and some applied skill at the
lever. You *could* just throw it into full reverse, but it would be
dangerous.

Skill at the lever. I love it. Don't you know the main engine valve
train was steam operated?

I assume commercial ships don't practice stop-and-lock or crashback
drills like a military ship does.

A stop-and-lock on a turbine plant takes a bit less skill, since all you
have to do is shut of steam on the ahead throttle and crack open the
astern throttle, then slowly open it further.

Good lord.

For those that have no idea about this here's a site:

http://www.tpub.com/content/fc/14104/css/14104_122.htm

Judge the depth of the Doug BS for yourself!

Cheers

Nav wrote:
I'd call it a backpedal when you now admit the inlet was not a vacuum
but at 9 or 11 psi !!!

Do you know the difference between

psi

and

psia

???

Take a look at any standard marine propulsion engineering text, turn to
the chapter on main propulsion condensers, see if you can find one that
runs at positive pressure.

DSK

Nav wrote:
Skill at the lever. I love it. Don't you know the main engine valve
train was steam operated?

You don't have a clue.

The main engine pilot valves were controlled by a lever which determined
the timing. The position of the lever controlled the duration & timing
of steam admitted to the cylinders and could be set from full power
ahead to full power astern. This was a standard set-up on recip steam
engines.



A stop-and-lock on a turbine plant takes a bit less skill, since all
you have to do is shut of steam on the ahead throttle and crack open
the astern throttle, then slowly open it further.


Good lord.

For those that have no idea about this here's a site:

http://www.tpub.com/content/fc/14104/css/14104_122.htm

Judge the depth of the Doug BS for yourself!

Please quote the section which you think proves I am BSing. Also, please
quote any references you have saying that the Titanic had clutches. Or
reduction gears, for that matter.

DSK

DSK wrote:



A stop-and-lock on a turbine plant takes a bit less skill, since all you
have to do is shut of steam on the ahead throttle and crack open the
astern throttle, then slowly open it further. Less things to break, too.

You would not disengage the main gearbox? Do you think the main turbine
gets spun backwards by the reversing turbine? Two other common methods
are CPP and clutches with reversing gears (the clutches are particularly
interesting from an engineering aspect).

Cheers

I know the difference between a vaccumm and and 9 psi! The inlet to the
turbines was not a vacuum Doug!

Bwhahahhahahaha

Cheers

DSK wrote:

Nav wrote:

I'd call it a backpedal when you now admit the inlet was not a vacuum
but at 9 or 11 psi !!!


Do you know the difference between

psi

and

psia

???

Take a look at any standard marine propulsion engineering text, turn to
the chapter on main propulsion condensers, see if you can find one that
runs at positive pressure.

DSK

otnmbrd wrote:

This becomes an engineering question and I'm not an engineer. However,
considering the mass involved, I'd assume that the process for reversing
engines running at full sea speeds (even recips) would involve a good
deal more than just "throwing a lever" G

Reversing only required pulling one lever to admit steam to the cylinder
of the "reversing engine" which in turn shifted the valve gear to bring
the correct eccentric into play.

Efficient running was something else entirely though, with adjustments
to the valve gear to set the desired "cutoff" of steam to balance
economy vs power.

Rick

DSK wrote:

Nav wrote:

Skill at the lever. I love it. Don't you know the main engine valve
train was steam operated?


You don't have a clue.

The main engine pilot valves were controlled by a lever which determined
the timing. The position of the lever controlled the duration & timing
of steam admitted to the cylinders and could be set from full power
ahead to full power astern. This was a standard set-up on recip steam
engines.



A stop-and-lock on a turbine plant takes a bit less skill, since all
you have to do is shut of steam on the ahead throttle and crack open
the astern throttle, then slowly open it further.



Good lord.

For those that have no idea about this here's a site:

http://www.tpub.com/content/fc/14104/css/14104_122.htm

Judge the depth of the Doug BS for yourself!


Please quote the section which you think proves I am BSing. Also, please
quote any references you have saying that the Titanic had clutches. Or
reduction gears, for that matter.


C'mon my little fish, you know that you were referring to other turbine
plants -it could not be otherwise unless your decription of a reversing
throtle applies to thne Titanic. OR are you now saying the Titanic had a
reversing throttle?

Man do you love painting yourself into a corner! I guess you don't know
about reversing gears, clutches and CPP's as common ways to give astern
propulsion. OR are you saying all turbine powered ships have a reversing
turbine!

Bwhahahhaha

Cheers