Prop wash,What do you think?

Well said!  Look forward to your new ideas.

Michael 

 Okay i'll admit to defeat,this round but i have another project in line to get this done.On the tamiya kit the outer rudder barely if at all lines up with the props.Then i want to do a dio as if the ship was under way not with all the a/c sitting on her deck in dry dock.As i seen alot of models done looks alright but i think it can be brought up a notch.The chances are that i might fail at this project but in my opion this is why we model to push the envelope and try something new.Maybe it will work and maybe it won't,but as the old addige says it's better to try and failed than to never of tried at all.I think i might have some pics of the new "PROP WASH" in about 4-5 days. But in hind sight i do agree it doesn't look right at all,and i do greatly appreciate everyone's opion.

True!

While I hate to comment negatively I must say the prop-wash doesn't work for me but I am also at a loss to suggest anything else.

Michael 

MJH wrote:

Surely the old trick of two tin cans joined by a length of string is the original (and most basic) form of sound-powered 'phone?

Yes it is, but the wire doesn't need to be kept taut to conduct the sound

Wow, we've totally co-opted the original subject of the thread!

Surely the old trick of two tin cans joined by a length of string is the original (and most basic) form of sound-powered 'phone?

I'm glad to have my recollections on this point confirmed.  I think the set of sound-powered phones we had at the Mariners' Museum dated from WWII, but I could be mistaken about that.  (If anybody's interested, I imagine the things are still there.)  They were pretty primitive; as I remember we set them up with twenty or thirty feet of wire between them, and had to yell into them to get even a faintly audible signal.  (That may have been due in part to their age, I suppose.)  But they most certainly did work.

jtilley wrote:

<<SNIP>> The sound-powered phones were carried on board American warships (I don't know how many of them, or at precisely what dates) as part of the damage-control equipment, to carry messages when the power was out.  <<SNIP>>

Sound-powered telephone networks are still installed on USN ships (can't speak to others).    It is one of the primary DC comm channels.  When the company I work for developed the Trident Submarine Command & Control training devices we had to implement a sound-powered comm network in addition to the electrically powered comm systems.  They were SP phones and had to simulate the shipboard SP networks.  We used tactical SP gear (to Government specs - so that when something broke they could go to the Storekeeper for replacement). 

Professor, sound powered phones are still very much alive and well aboard Navy ships. They are used as primary communications throughout the ship for battle, damage control, engineering, air operations, etc. and are very reliable. They don't require any external electrical supply although they do sometimes will have an amplifier in line for very long circuits that might get a weak signal. The phones come in different configurations, from the basic handset you described to the headphone/yoke mounted mouth piece you see in documentaries and movies.

They are actually sound powered. A diaphragm is attached to a magnetized needle which in turn is inserted into a coppper wire coil. As the phone talker speaks the diaphragm vibrates causing the needle to move back and forth through the coil inducing an electrical current, which causes the opposite effect on the receiving phone creating sound. It is so simple. One interesting feature of this system is that if an earpiece or mouthpiece is broken, the phonetalker can symply listen and speak on the surviving earpiece/mouthpiece. These phones have survived in the same basic form for at least 70 years if not a lot longer. The disadvantage is like I mentioned above, the longer the cable, the weaker the signal. That is why the phones sometimes have an amplifier installed somewhere along the circuit or actually installed on the phoneset itself (AA battery)

I was surprised to learn that the sound-powered telephone actually existed.  A pair of them got donated to the museum where I used to work; the registrar (an Army veteran who'd worked in communications during WWII) hooked them up, and we actually got them to work.  They looked, as I remember, pretty much like ordinary old-fashioned telephone handsets, with wires in the usual places.  It seems that the sound of a human voice is capable of generating a tiny electrical charge (related to the piezo-electric effect, I imagine), which can be carried across a wire and turned back into sound at the other end.  The sound-powered phones were carried on board American warships (I don't know how many of them, or at precisely what dates) as part of the damage-control equipment, to carry messages when the power was out.  On the set we tried out, the person doing the talking had to yell into the mouthpiece for the person at the receiving end to get even a faint signal, but the things did work.

Go to the IC or EM shop and get some sound powered phone batteries. 

Or, tell the guy to feed the shaft seals.    arf  arf

subfixer wrote:

Prop wash is what you send new squids out to look for, like fifty feet of waterline, a bucket of steam, relative bearing grease, three fathoms of chow line, padeye torque wrenches, etc..

HT punch, mail bouy

subfixer wrote:

Prop wash is what you send new squids out to look for, like fifty feet of waterline, a bucket of steam, relative bearing grease, three fathoms of chow line, padeye torque wrenches, etc..

HT punch, mail bouy

Beware of Jet blasts and Propwash when on the flightdeck.

Prop wash is what you send new squids out to look for, like fifty feet of waterline, a bucket of steam, relative bearing grease, three fathoms of chow line, padeye torque wrenches, etc..

Ummmmm ... why? That's my main question - unless you want the ancillary things like the base, prop cavitation, etc., instead of your excellent-looking build to be the focus.

It looks hokey! 

If the ship was cavitating that much there is all sorts of lost propusion efficiency, not to mention acoustic noise generated.   Most of the bubbles and froth generated should be from the blade tips, not from the trailing edges.   As a result the propwash would look more like a spiral which follows the prop tip path.  

The white water seen assocoated with wakes is actually most often caused by the hull displacement.  

Add to what was mentioned about the rotation direction, the rudders should go through the propwash - not to the side of it.

I've thought of doing something along this line, but I've thought the density of the cavitation bubbles should be similar to the spiral of waste when you bore into a piece of plexiglas with a drill bit.

Less is more in this instance 

 

For the two starboard side props, the wash should be twisted in the opposite direction.  It loks like you twisted the caulk on all four props to the right, or clockwise.  For the starboard side props, the caulk needs to be twisted to the left or counter clockwise.  The direction of the twist should match the pitch angle of the blades.