FSX
good find seahawk, but thats on an S-14 or an S38 class.. S-100s were never converted. They were built with the hardshell in place..Originally Posted by Seahawk72s
good find seahawk, but thats on an S-14 or an S38 class.. S-100s were never converted. They were built with the hardshell in place..
I guess what I'm thinking is I wonder how much they changed the wheel house from an S38 to S100..?
Here is what I'm thinking about for the revised panel.
1) The basic cockpit with just icons for pop-ups.
2) A small console pop-up with the tachs, MPs & Speed.
I will revise it tomorrow to make the gauges bigger in the same size console.
3) Don't mind all the switches. I've been making more switches to cover experiments with different lights.
For example a deck light for port and red VC lights for the helmsman and cockpit.
4) The engineers pop-up console with more engine controls including fuel shut off, start buttons, fuel/oil pressure,
coolant temp, etc.
5) The rest of the original pop-ups, radios, compass, GPS, etc.
I like it. Lots. good job..
I put the boat through afsd as suggested to me by Bjoern and saw that there was only 6.98 inches of Manofold pressure, then realized, this things a diesel. it has fuel injection. Diesels dont suck.. So THAT part is cool. It's arunning low top end of 39 knots and high top end of 49 knots, so, that averages out to 44, 45 knots after we remove microsofts bullhockey, and thats cool too.. Theres two parts that together, have me stumped at the moment. I reprogrammed the engines in both the config and the airfile, to official specification ( MB-511 https://oldmachinepress.com/2017/03/...arine-engines/ ) and the numbers are off the charts. 26000 pounds of thrust. 12000 rpm on the propeller. and the ship simply wont slow down. it's like its on perpetual diesel runaway, and with a fresh supply of cold water to keep it from burning itself up, it'll run till the gas runs out, in about Ohhh, 800 miles.. I just dont get it. SO, I'll keep working on that tomorrow. It occured to me that when i was growing up on the Illinois river that many of the river boats that went up and down it were little more than flat platforms ( and expensive furniture ) sitting on top of pontoons, so, maybe this thing is a boat after all..
Direct drive propellers or gear reductions?
Thats a very good question sir. I wanted to make it direct drive, as the only gear reduction values i could find were for the daimler benz DB602; a 1300 pound little brother to the MB-511 ( which weights 10000 pounds ) except made for aviation purposes. It has a gear reduction of 1.5:1, which i'm experimenting with right now. The main issue i'm having is that when the "flight" first starts, the boat is well behaved and sits there like a good little boy scout. But as soon as you increase the throttle, thats it. You accelerate to 44 knots and stay there, no matter what you do too the throttle..
Afsd is giving me the most insane readouts and frankly, I'm completely confused..
In the photo below, afsd is on the left. the center is aircraft.cfg and the right is the air file.. I've got my ducks in a row, they're just wild ducks..
I would suggest getting RPM readouts correct first. That diesel has turned into a turbine at 45842 shaft rpms. :-)
I t would probably help I reckon to add a bunch of Prop MOI as those things were seriously heavy. That might help slow down those 20- 410 Cu In cylinders.
EDIT: Are you certain the prop diameter is correct, or could it be a single blade diameter you read. Those propellers are huge.
I've worked and been an engineer on several WW2 era "small boats", landing craft and tugboats. Quite a few of those old boats were still in use in the 80s. Most diesel engines of the period ran with very slow rpm. The US ones of the period, 1800 rpm is what the governors were set to for normal use on the smaller ones. Larger engines tended to run slower (the mains on the tugs ran 720 rpm max, idled about 250 ish)
On reversing, variable pitch propellers were invented in the 20s, but I'm not sure when they came into use on boats though or if anyone actually used them in WW2 as most examples I ever ran into were postwar builds.
The schnellboots are the best looking and designed torpedo boats of their period IMO. If this can be released, I'm going boating and will have to add a boatyard behind the Merc Air hanger.
(One of our running gags back in the CFS 1 online days in the Cantina here was about a Merc Air affiliated Kriegsmarine E-boat skipper we called "Gunter" and how much he'd charge for "rescues" of pilots shot down over the Channel.)
Let Being Helpful Be More Important Than Being Right.
We'll be releasing it at some point Willy.. I've got very poor skills any more but I'm pretty determined. It'll never be a "great" boat as there are many things I'm not, and I'm not a 3D artist, and I'm not a painter. But, someone had to build it. Right?? Paul Dominique did the hull and turtle-back for me and forbid me from saying anything, but its been five years.. I built everything else. But that was a long time ago and i've grown much more limited in ability than i was.. Bear with me.. we'll get it out there..
Pam
Still working on the gauges and lights.
Took her out for a night spin.
Have overboard water discharge effect tied to engine operation.
Since you took the "Cat", needed to give him/her some competition...lol
Thats the surprising thing. Last night while i was researching it i found data that indicated the props on S38 had an MOI of 6.98. That made no sense to me at all.. My Original calculations based on the estimated diameter placed the MOI at 109, BUT, that diameter turns out to be little more than a laymans observation ( and an eyeball guess at that ) because somehow, magically, prop diameters change while the boat is running. At least, thats what was being said in an article i read about what to consider when buying a prop for your boat..
In a sense, I can understand certain things about props. It's like, it takes very little force to turn a screw through a piece of wood, but the amount of longitudinal force it applies to that wood, is amazing. the same would apply to the propeller on a boat. If I look down from above on a propeller, it's almost like the blades and stem were carved from a single cube of brass as theyre almost as deep, as they are tall.. Unlike aircraft propellers, these things are literally screws designed for water.. they have very little resistance but they move a lot of water, and it seems that they use the waters in-compress-ability as a means to propel the boat as they move water through their blades, and push it against the water behind them. But heh. I know i've got a screw loose so i'm most likely wrong..
So the beam on the s-100 was 16.6 feet. There are three screws across that which combined cover between 75% to 80% of that breadth, so your correct. those screws were at least 4 feet wide and more likely 4.5 feet wide each.
now how much that block of brass weighs is another question. I would estimate around 450 pounds to 500 pounds each, based on that simple diameter and weight, the MOI comes out to being 71.0, unless I made some early morning before coffee mistake, which is quite possible.. that moi estimate is based on a roll coefficient of .238 with a diamets of 4.5 and a length of 4. somehow weight never seems to come into play when doing moi's for fsx.. I dont understand that. If I factor in the weight, that 71 all of a sudden turns into something more along the lines of 800, because the moi of a screw is going to be based more on weight and resistence with the resistence of the water at five feet depth being approx. 18 pounds per cubic inch and the 450 pounds of the prop all applying torque against the engine, (((627875.7764 ))) which could explain why we need 8000 cu inches of displacement to turn one screw.. Again, i'm probably wrong.. Theres nothing more dangerous than an idiot with a calculator, but hey, you may have saved me here.. Let me give that result a try..
20 years of Naval engineering and if someone told me that the screw diameter changes when turning, I'd have looked at them like they'd landed on their head in the bilges from the top of the mast.
Just as a "reference point", on a US Navy 50ft Utility boat, the screw was about 18" wide, turned by a 210hp Gray Marine 6-71 2 stroke diesel governed to about 1800rpm normal maximum. The transmission (like most boat transmissions) was just for providing a reverse function, so the screw would also have turned at 1800rpm. At 1800 rpm with a clean bottom and calm water, 10 to 12 kts was about as fast as it would go.
The older WW2 engines had an "emergency" setting on the governor that would allow a few more hundred rpm, but I'm unsure of the HP as it was years ago.
Let Being Helpful Be More Important Than Being Right.
Thanks willy. I mean, I've got lots of reason to doubt myself, but jeez.. I think what that article was doing was taking cavitation ( ? ) into account, which can grow beyond the diameter of the prop, and if the prop is shaped right, even shrink to within the diameter of the prop. I think what they were talking about wasnt so much the physical prop itself, but the cylinder {??} of thrust it creates..
I'm pretty certain of the 4.5 foot diameter and rpm is given at 1630 max. Its the weight i'm not able to estimate as I dont normally try to lift blocks of brass that size..I can imagine that they weigh around 600 pounds each but thats as wild a guess as i've ever made..
Hey Willy.. You said you were a marine engineer?? Wanna give this thing a shake down and tell me where i'm off and what i need to do??
I love it.. Actualy, since i dont have any teeth, maybe i should have a picture of Snagglepuss on there ::LOL::... I'm satill ripping deeper and deeper into the fde.. I finally got it to slow down when i reduce the throttle, without using reversing props or spoilers ( that i'm aware of ), but she's still a very troubled little girl.. I've asked Willy if he'd be willing to shred it for me and tell me where i'm wrong so i can fix it. Milton got me moving in the right direction ( thank you Milton)but it's still pretty rough.. Didnt know you were partial to cats too.. You do know those are flotilla insignia right?? Ther boat I'm driving is the Lang, but i left the giant H and the word Lang off the turtleback as I dont really like it
How many blades on the prop? I'm assuming it was brass or bronze.
Let Being Helpful Be More Important Than Being Right.
A prop for a 80ft Elco PT boat:
Outboards: 30" diameter/30" pitch, Center: 28" diameter/28.5" pitch
Weight: 61lbs
I'm not so sure that the Schnellboat prop would be 4.5ft. I'm thinking it should be a lot smaller.
Let Being Helpful Be More Important Than Being Right.
S-130 was 114 feet long, 16.6 feet wide and weighed 200000 pounds ( mahogany, go fig )..
it really is massive.. Could be either bronze or brass but I'm assuming brass..
This is about 14 feet of bottom with all the props in place..
So yeah, they're big. If i put them edge to edge, they'd take up between 75 and 80% of the entire beam so i'm thinking 4.5 feet is close.. could be wrong..
No wonder they were so fast. There's enough prop there for a destroyer.
Very fast pitched too!
Let Being Helpful Be More Important Than Being Right.
yeahhh, I'm thinking 60* or so, but fsx doesnt like that. 60* wont move me an inch, at least not with fixed pitch. I'm thinking the solution to that particular hurdle is to mathematically reduce the depth of the prop to that of a standard aircraft prop and take a measurement of the degrees at that point. I'm guessing between 30 and 40*. I dont know really..
I dont know what the fastest conventional ship is in the navy as i know some of those numbers are classified, but i do knopw that the dutch had a patrol boat in the seventies ( Willimoes class ) that could easily do better than 45 knots.. The video below tries saying theyre doing 40 knots, but i dont believe them. you can hear the turbines spinning up when they reach a point they will no longer swamp the camera boat..
I noticed with engine start-up there is a brief puff of smoke.
From what I can tell this is happening just about where the stbd. underwater exhaust is..?
How is this happening as I don't see any smoke or effect defined in the aircraft.cfg.
From the drawing the two exhausts on the port side are under water with some form of water discharge,
above water line for each engine..?
Did gauge work, cosmetics on the panel and added two hatches.
Just about have the gauges ready to send the whole thing over to you for a try.
I've noticed that too, and too be honest, I havent a clue where its coming from.. It'll be something i have to figure out once it can fully reverse .
I dont have the gauge yet. didnt know you sent it.. My bad.. Been so deep into this fde i've been sort of out of it.. Let me look again..
Not sent yet, give me about an hour...
Members who have read this thread: 1
Posting Permissions
Bookmarks