A Moebius Skipjack from the land of OZ...

[alad61]

Myron please don't get me wrong about the sas system. It absolutely works!! Any early issues I have had have pretty much been me. If you go long & deep then maybe the gas backup installed as well is good peace of mind but otherwise the SAS does what David intended it to do.

[vital.spark]

David, How about the Gas System with SAS as an option!

[He Who Shall Not Be Named]

Nope. With the exception of the KILO SD and the 1.25 SD's all are SAS as provided, with the option of a gas retro-fit.

M

[alad61]

Mmm gas... It's an added cost through purchase and waste If not all used. Then you need to remember how many times you may have blown the ballast. Also what if the transfer from the can to tank on the SD. There will be that one time your lpb breather is below the surface and there isn't Enough gas to blow the ballast, then what?? Nope no more gas for me.

[vital.spark]

I have 3 subs with the gas system and they work!! Sooner or later you are going to wish you had it!!

[alad61]

I am sorry if I offended you as that wasn't my intent.

For the record I have two boats with gas, one dynamic, one with a pressure tank & slow release pinch valve and the SAS. I have had a gas one go down to the mud, threw the emergency gas switch but no sub to be seen. However it was found though and to this day I'll swear in court that there was gas in the emergency tank but when retrieved the tank was dry? I have also had successful ballast blows with the gas.

However with my ballast & trim issues the other day my Skipjack went down to the bottom, fortunately very near the dock but still about five feet deep. I threw the pump switch and up she poped :wink:

All I am saying is that for me I will be going with the SAS system where ever possible for future subs.

[vital.spark]

Alec, no offense taken. I just like pulling Davids Leg! As I posted before, I like to follow the KISS princaple. David did a great job on perfection the SAS system but for me any extra holes in a boat can be a future source of problems. I've done a lot of offshore sailing including Hong Kong to San Francisco back in 1973. I can tell you from first hand experiance that a stuck check valve in the middle of the Pacific is no fun with water lapping over your feet!

Regards to all

Myron

[He Who Shall Not Be Named]

Myron's point about too many holes in the SAS system is valid, and a source of concern for the operator of a model submarine employing this type ballast sub-system. However, the inclusion of the safety float-valve in the plumbing of the Caswell-Merriman SAS equipped Sub-drivers addresses the potential of a flooded induction line -- regardless of cause. The SAS, as compared to the gas or Snort ballast sub-systems, is indeed more complicated. But that added complexity is, I think, offset by the SAS sub-systems ease of use and ability to blow out ballast water from depth or at the surface. The SAS ballast sub-system is a simple and reliable means of managing ballast water without the need of gas and gases attendant trim and logistic problems.

One more thing: I want to take this opportunity to remind everyone that the SAS ballast sub-system I came up with is very much a copy of the fine work done by Manfred Reusing -- he's the guy who lead the way. I simply followed.

And it's no accident that Manfred's system is very much predicated on what actual combat submarines use to manage their main ballast tank water. The SAS very much emulates the design and function of 'real' submarine ballast systems.



M

[Slats]

Myron's point about too many holes in the SAS system is valid, and a source of concern for the operator of a model submarine employing this type ballast sub-system. However, the inclusion of the safety float-valve in the plumbing of the Caswell-Merriman SAS equipped Sub-drivers addresses the potential of a flooded induction line -- regardless of cause. The SAS, as compared to the gas or Snort ballast sub-systems, is indeed more complicated. But that added complexity is, I think, offset by the SAS sub-systems ease of use and ability to blow out ballast water from depth or at the surface. The SAS ballast sub-system is a simple and reliable means of managing ballast water without the need of gas and gases attendant trim and logistic problems.

One more thing: I want to take this opportunity to remind everyone that the SAS ballast sub-system I came up with is very much a copy of the fine work done by Manfred Reusing -- he's the guy who lead the way. I simply followed.

And it's no accident that Manfred's system is very much predicated on what actual combat submarines use to manage their main ballast tank water. The SAS very much emulates the design and function of 'real' submarine ballast systems.

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M

Myron and others I too have to jump in here.

David will tell you, that his number one PITA client - ME - has required a long time convincing on the merits of SAS over gas backup. Trawl the search functions on this site for the rantings in this regard. :pop Entertaining stuff.

I have just order 2 new SAS SD's with NO GAS backup. AND SAS fittings to retro fit another SD. I admit its going to be fun wrangling the snorkel valve mechanism inside a 1/72 Permit sail - but will see.

Everything I have purchased from David - works as intended. Guys, I'm pretty much as cautious as they come, but the SAS system I believe is state of the Art and a big leap forward - taking a great design from Manfred and making a prefabricated system available to many. Besides if it doesn't work I'll have David's legs broken.

BTW -where's my order you bum?

[He Who Shall Not Be Named]

work'n on it. Enjoy your winter!

M

[vital.spark]

Dsvid,
You stated "The SAS very much emulates the design and function of 'real' submarine ballast systems.

Please see the attached page which clearly shows that the ballast tanks on our fleet boats were blown from the high pressur air systm taken from the 3000 psi manifold reduced to 600, 500, or 225 psi where necessary for different operations.

http://www.maritime.org/fleetsub/air/foldout/fig2-01.htm

Regards,

The s--t stirrer

Only in extremis.

Normal blow was to squirt some MP air into the bow buoyancy tank, start the low pressure blower (taking a suction on the boats air) and discharging into the main ballast tanks, popping open the main induction soon as the fairwater broaches, and ventilate the boat. Pretty much the system Manfred came up with.

M

[vital.spark]

Thank you David,

You say a squirt of MP air. To me, this is the gas system from the on-board bottle.

This chapter explains the system. http://www.maritime.org/fleetsub/air/chap1.htm#1A

Without the on-board gas system you are not emulating the real thing! Dah

I hope you are still my Friend?

[He Who Shall Not Be Named]

Sure. No sweat. Without challenge there is no progress/knowledge/clarification.

M

[Slats]

Alec,
interested to know the source of the leak you had?
Was it SAS related or some other seal issue?

Also if you had water in the SAS induction line did the boat still surface using SD air ok?

Thanks

John

[Slats]

As I await my 2 news SAS subdrivers, can't help but think re the size of the float valve on the head valve that I will inevitably have to build / modify it for inclusion in the 1/72 Permit sale (around half or a bit less than the real estate of the Skipjack).
Am toying with the idea of using a tyre valve (same as we use on the Subdrivers to vent overpressure on closure), but with spring removed and an actuation by smaller float. Other idea is to use a small Oring lining the pipe and atop the float having a small ball (like that used in the torpedo system), to form a male female fit.
Of course I'll try David's way first but am also wondering about getting the open/close activation point a bit higher up. Currently the LPB / gas system affords the full length of the scale snorkel, whereas SAS activates a closed head valve just beyond deck's awash. Any suggestions?

I note also the Permit's design plonked snorkel as the forward most mast, that is forward of the sail control area and unpopular with crews conning the boat up there when surfaced. Perhaps this snorkel unit with its head top fitting can be made to work in scale?

Cheers

John