Martin Model 307 "Sea Mistress"

With regards to this report, it seems not to be a specific type, but a model,
that was made for testing, if reasonable performances in flight and at sea
were compatible and such a design possible.
 
Martin Model 307 SeaMistress

Kapryan, Walter J. et al.Aerodynamic and Hydrodynamic Characteristics of a Model of a 500,000-Pound High-Subsonic Multijet Logistics Transport Seaplane April 1961

Summary:
Aerodynamic and hydrodynamic tests have been made of a 500,000- pound high-subsonic multijet logistics transport seaplane design conforming to the transonic area rule. The aerodynamic results show that acceptable stability and performance characteristics can be obtained on a high-subsonic-speed flying boat. Reasonable lift-drag ratios can be obtained up to Mach numbers of about 0.90. Additional improvements in lift-drag ratio and longitudinal stability characteristics can be obtained by small refinements in the area distribution. The hydrodynamic behavior of this design was determined to be generally satisfactory. Preliminary tests indicated that afterbody suction forces introduced some longitudinal take-off instability and high-speed resistance great enough to preclude take-off without afterburning. How-ever, the addition of a small auxiliary step to the afterbody slightly of the main step improved the stability and reduced the resistance to the point where satisfactory take-offs could be made without afterburning.
 

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Triton said:
Martin Model 307 SeaMistress

Kapryan, Walter J. et al.Aerodynamic and Hydrodynamic Characteristics of a Model of a 500,000-Pound High-Subsonic Multijet Logistics Transport Seaplane April 196

My dear Triton,

but in Martin list,the number 307 was unassigned to aircraft;

http://www.marylandaviationmuseum.org/pdf/Models.pdf
 
According to Stargazer2006:

Stargazer2006 said:
Finally I found the Martin Model number for the Seamistress transport project, which was missing in the official listing from the Glenn H. Martin Museum. It was the Martin Model 307, as found in the book Attack from the Sea — A History of the U.S. Navy's Seaplane Striking Force by William F. Trimble (Naval Institute Press, 2005).

Verified at GoogleBooks on Page 107 of Attack from the Sea — A History of the U.S. Navy's Seaplane Striking Force:
http://books.google.com/books?id=Ei-d4ou-GesC&printsec=frontcover&dq=Attack+from+the+Sea+%E2%80%94+A+History+of+the+U.S.+Navy%27s+Seaplane+Striking+Force&hl=en&ei=uZX6TbWOIvTYiAKMx7CNBQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCwQ6AEwAA#v=onepage&q=307&f=false
 
If these models are in the same scale, then it shows just how big the unbuilt Model 307 SeaMistress was supposed to be!
 
Hi,

http://archive.aviationweek.com/image/spread/19570916/27/2
http://archive.aviationweek.com/image/spread/19570902/15/2
 

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The United States and it's allies could well use the SeaMistress right around now.
 
To where? You write that it would be useful now. Could you give an example where one would be preferable to current large land based cargo aircraft or COD aircraft?
 
What were the dimensions and weights?

One of the links says a gross weight 200 to 300 tons and maximum payload of about 130 tons.
 
To where? You write that it would be useful now. Could you give an example where one would be preferable to current large land based cargo aircraft or COD aircraft?

Intercoastal transport in the Continental United States for urgently needed supplies and personnel. Transoceanic transport for same as well.
 
To where? You write that it would be useful now. Could you give an example where one would be preferable to current large land based cargo aircraft or COD aircraft?

Intercoastal transport in the Continental United States for urgently needed supplies and personnel. Transoceanic transport for same as well.

But why a giant seaplane? There are lots of conventional cargo aircraft (and airliners) and suitable airfields almost everywhere with easy access to regional/local road nets. That's the foundation of Amazon/FedEx/UPS rapid delivery services, and for the most part those are actually working amazingly well. What we don't have in the US is cargo handling infrastructure next to waterways that are not already seaports.

There is no evidence that cargo transportation infrastructure is being overloaded right now. What is overloaded is warehouse sorting/packing/shipping from certain large sellers (Amazon...), but that's because there aren't enough people to get stuff out the door or, in some critical categories, because there isn't inventory to ship. Sole exception may be last-mile delivery in some places -- for example, it's nearly impossible to schedule grocery delivery in some urban areas, but a giant seaplane isn't solving that problem.
 
Oceanfront urban real estate, where a giant seaplane would tie up, is scarce and valuable. Concrete on the prarrie is cheap and plentiful. The tonnage moved per acre (or linear foot) through a seaplane port per day would be miniscule compared to a conventional dock, much less a intermodal container port. Aside from that seaplanes are less efficient than land-based aircraft and tend to sink when they run into floating objects not often found on runways.
 
Civilian air & sea cargo capacity, or what's left of it, is pretty severely stretched at the moment. Also, the USAF airlift fleet, and military airlift in general, was cut back during the Obama administration because it was assumed that civilian contractors would be able to take up the slack. That proved a bit optimistic even then. Not to mention even before that, airlift capability had never quite recovered from the 'Peace Dividend' years, not even during the relatively free spending days of the 'War On Terror' (most of the available funding was poured into such things as 'Transformation' and 'Nation Building').
 
Civilian air & sea cargo capacity, or what's left of it, is pretty severely stretched at the moment. Also, the USAF airlift fleet, and military airlift in general, was cut back during the Obama administration because it was assumed that civilian contractors would be able to take up the slack. That proved a bit optimistic even then. Not to mention even before that, airlift capability had never quite recovered from the 'Peace Dividend' years, not even during the relatively free spending days of the 'War On Terror' (most of the available funding was poured into such things as 'Transformation' and 'Nation Building').
What does "stretched" mean - that there's little excess capacity? Another way to phrase that is "supply is well matched to demand". Global civilian air & sea cargo capacity is at an all time high and if shipping capacity were a significant constraint on trade, there's no reason more ships couldn't be built (shipyard capacity isn't stretched) and more 747s hauled out of desert storage for cargo conversion (or new ones built - I think Boeing is currently cranking them out at less than 1 per month). If "what's left of it" refers to the US-registered fleet, that's a different point and is mostly a matter of legislation.
USAF airlift capacity is most needed during a crisis, when the cargo might be needed far inland and maritime facilities might be saturated.
Anyway, I don't see how cargo seaplanes make a practical contribution. They're charismatic, but so are steam locomotives and windjammers.
 
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Less than ideal, to be kind, for commercial use, but if you use purpose built lighters as depicted in the last pic, I can see some interesting EABO tie-ins that open up possibilities.
 
Supply chains (especially JIT based) around the world are collapsing because transport links, whether by air or by sea, are intermittent at best.

A couple of stories from the BBC to illustrate the current transport situation:


 
I really think you're misunderstanding the problem. Both articles are pointing to a lack of demand for shipping, in fact there is currently a massive surplus of capacity for both sea and air shipping. The breakdown in JIT supply chains isn't due to transportation problems but supply disruptions, mostly in Chinese factories that were closed or running well below capacity during their shutdown, and demand collapses, where final assembly or sales locations are closed in (mostly Western) consumer economies.
 
Intercoastal transport in the Continental United States for urgently needed supplies and personnel. Transoceanic transport for same as well.
Aren't most major airports on the coasts on or very near bodies of water already? SFO, JFK, SEATAC, Dulles, Boston Logan, to name a few. Is the Mistress to pull out of the water onto a taxiway at one of these? Where's the advantage over conventional aircraft?
 
Intercoastal transport in the Continental United States for urgently needed supplies and personnel. Transoceanic transport for same as well.
Aren't most major airports on the coasts on or very near bodies of water already? SFO, JFK, SEATAC, Dulles, Boston Logan, to name a few. Is the Mistress to pull out of the water onto a taxiway at one of these? Where's the advantage over conventional aircraft?
Maybe islands, or smaller or more remote towns and cities? Places that don't have large airports, but have seasides or big enough lakes with docks the aircraft can pull up to? That kind of thing is part of the remit for the US2 in Japan.
 
Mainland China would love to fly a fleet of Martin Sea Mistresses to supply all their “islands” in the South China Sea.
Many of those “islands” are only dry during low tide and too short to build runways.
 
Mainland China would love to fly a fleet of Martin Sea Mistresses to supply all their “islands” in the South China Sea.
Many of those “islands” are only dry during low tide and too short to build runways.
Avic AG600. They're making a fleet of them. Still in pre-production testing, but should be certified and in production in the next couple of years. Of course it is only a bit over 20% the weight, but It's a bit bigger than the ShinMaywa S-2. The only thing bigger is the Berieve A-40/Be-42, which is still "in development" after some 40 years. But Russia may be deploying some soon. Of course they also said that 10 years ago.

Beriev has had some even larger designs than the Sea Mistress, but they've never found funding.
 
I really think you're misunderstanding the problem. Both articles are pointing to a lack of demand for shipping, in fact there is currently a massive surplus of capacity for both sea and air shipping. The breakdown in JIT supply chains isn't due to transportation problems but supply disruptions, mostly in Chinese factories that were closed or running well below capacity during their shutdown, and demand collapses, where final assembly or sales locations are closed in (mostly Western) consumer economies.

I'm not sure if that is indeed the case. Earlier on in the crisis for example, other countries in the region were trying to cash in on China's production capacity being severely impaired, but ultimately they were unable to really do so, even before the virus reached them. This was because even then supply chains, both for their finished products and the raw materials and/or components they needed to make them in the first place, were beginning to break down due to steadily increasing transportation issues (not to mention that a lot of the said raw materials & components was still originating in the PRC). That's the problem with Just In Time supply chains, any disruption to transportation links heavily impacts on them, to the point where they can collapse altogether. JITS is not actually that flexible when you come down to it, the claims of it's proponents not withstanding (putting it politely). And I think that you may have misread the article yourself. There is no 'surplus of capacity', rather only ships and aircraft that have been indefinitely taken out of service due to the worldwide lockdown (or in a fair few cases direct exposure to the coronavirus [people or affected areas] itself). There is little prospect at the moment of those civilian owned & operated conveyors (those that survive intact) coming back into play anytime soon.

With a cargo aircraft such as the SeaMistress, one could bypass high risk areas while getting vital cargo quite close to them or other destinations.


Aren't most major airports on the coasts on or very near bodies of water already? SFO, JFK, SEATAC, Dulles, Boston Logan, to name a few. Is the Mistress to pull out of the water onto a taxiway at one of these? Where's the advantage over conventional aircraft?

From what I hear the bulk of those are now (belatedly) effectively closed for the duration. The few that are still operating in any meaningful manner have very limited flights indeed and that includes cargo.
 
Via the Martin P6M Seamaster thread:
supahseaplane-jpg.74969

(h/t RyanCrierie)
 
Ebay has the wind tunnel model of the Sea Mistress up for auction.

 

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I took these pictures at the Pax River Museum many years ago. I assume it to be a permutation of the Sea Mistress or other Jet seaplanes.
 

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Interesting that the model at Pax River has a "Y" tail variation.
 
The WTT model on display at Patuxent River Naval AIr Musuem looks similar to the BuAer DR-77 water tank model, but differs in many aspects, most notabley the empennage and the extended leading edge intakes. Photos taken in June 2022.
 

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