Talk:Martin P6M SeaMaster

Rating

Needs an infobox, fairly decent information but details, details. Regrettable that the importance is "low" but as a "failed type" and obscure to boot it's not as important as some others, despite being one of the great What-Ifs and (not NPOV) worst decisions-to-cancel ever made (/not NPOV). - Aerobird 04:29, 16 December 2006 (UTC)

You have details. The airplane was magnificent. It's performance was astounding given the problems inherent with seaplanes. The decision to cancel was fully justified. The program had slipped for too long, was so far over budget that the number of aircraft to go into service would have been too small.

-- begin new comment by different editor-- The P6M was a result of inertia and defense politics. The Navy wanted to have a strategic nuclear role, and before the A3D it did not have a credible carrier aircraft to perform it. The Navy had always had seaplanes (it was, after all, the Navy) and a 'jet' seaplane just seemed logical in 1950.

I will fix the info box problem.Mark Lincoln (talk) 15:38, 16 August 2011 (UTC)

The P6M was part of a bigger plan than just giving the Navy a nuclear strike capability before the A3D. The AJ had already given it a carrier based nuclear strike capability. The P6M patrol, minelayer and bomber, R3Y transport and F2Y fighter were to constitute a sea based "Seaplane Striking Force." The demise of the P6M was more a matter of failing to deliver the product in time. There was Pentagon politics involved, but the ultimate axe came due to the 29% reduction in defense funding by the Eisenhower Administration and the development of the Polaris Missile System.

Seaplanes were a marginal part of Naval Air. The other two elements of the Seaplane Striking Force, the F2Y which was to defend the sea bases, and the R3Y transport were miserable failures, one for hydrodynamic reasons, the other because of it's engines.

This left the Seamaster without a rational aside from it's ability to lay precision mine fields and perform nuclear strikes.

Inertial navigation systems, high specific impulse solid rocket motors, and nuclear power enabled the creation of the Polaris Fleet Ballistic Missile boats.

The Submarine community was far larger than the flying boat community. The Polaris was an infinitely superior strategic nuclear strike system. The A3D and upcoming A3J satisfied any need for a 'fleet' nuclear strike capability.

Eisenhower wanted to cut US defense spending from absurd levels to reasonable ones and the P6M was one of many systems to be cut for sound reasons.Mark Lincoln (talk) 13:53, 16 August 2011 (UTC) I have some books in my library which will allow a quick solution to the lack of references and citations.Mark Lincoln (talk) 13:53, 16 August 2011 (UTC)

Anyone disagree or have input?Mark Lincoln (talk) 13:53, 16 August 2011 (UTC)

Reference?

This article states: "In the age of the ICBM and SLBM, the manned bomber had become an expensive and unreliable nuclear weapon delivery system." Sounds like someone's opinion - don't think the DoD or Congress think this is the case. If they do, why are they spending huge amounts of tax dollars building and maintaining a land-based strategic bomber fleet.— Preceding unsigned comment added by 2601:801:300:7520:B027:3E10:13E2:E7AC (talk • contribs)

I think your comments are valid and I've citation-tagged the passage. Carguychris (talk) 19:11, 26 August 2023 (UTC)

J58 engines

This document, an extended version of The Oxcart Story (declassified at the same time), claims that the Seamaster originally intended to use the J58. No such claim appears here, where the larger engine is the J75.

Does anyone know more about this? I believe the Oxcart version is wrong.

Maury Markowitz (talk) 22:53, 11 December 2008 (UTC)

You are correct. There would be no use for a turbo-ram jet on the P6M. I have no idea where the idea might come from aside from a 'source' which contained a typo (8 instead of 7).Mark Lincoln (talk) 13:39, 16 August 2011 (UTC)

According to this [1] 1954 Flight news item, the P6M was originally due to have Wright J67 engines. — Preceding unsigned comment added by 80.7.147.13 (talk) 18:50, 12 January 2014 (UTC)

The J58 was originally developed by the Navy, and was later modified for the SR-71. It could well have been intended for the P6M at some point. - BilCat (talk) 23:01, 12 January 2014 (UTC)

Outside loop

Despite a highly detailed information about one of P6M crashes, something is strange at the following article statement: "The first prototype, BuNo 138821, c/n XP-1, disintegrated in flight at 5,000 feet due to horizontal tail going to full up in control malfunction, subjecting airframe to 9 G stress as it began an outside loop...". Well, as far as I know, if a horizontal tail goes up (i.e., the elevator or the whole horizontal assembly deflects upward), the aircraft makes an inside loop, not an outside one. Since I have no detailed information about this particular event with BuNo 138821, I cannot correct or edit the above mentioned text. Can someone with specific familiarity/information about that incident review/revise that statement regarding that control surface logics I've mentioned? Thanx. RobertoRMola (talk) 02:38, 16 July 2009 (UTC)

The problem is in wording. Due to an actuator failure, the stabilizer was driven rapidly into a full nose down position which which caused a violent pitching movement. This cause the lower wing blankets and spars to buckle in compression. This resulted in the wings failing at the roots. This resulted in the floats on the wing tips 'clapping' beneath the fuselage. The engine became detached. The tail hinge failed with the horizontal stabilizer separating from the vertical stabilizer. The maximum G-force was -9Gs. The fuselage impacted the water about 20 seconds after the runaway stabilizer and with a force of 100+ Gs. The two test observers both ejected but only one survived. Though their ejection hatches had been actuated, only one of the pilot's had cleared. Neither pilot initiated an ejection and both were at the controls upon impact. The kind of bad day that was all too common in test flying in the 1950s.Mark Lincoln (talk) 15:36, 16 August 2011 (UTC)

Now I got it. I confused things a little bit: what was gone up was the whole tail, not the elevator... My mistake! --RobertoRMola (talk) 18:54, 16 August 2011 (UTC)

P-6 and scrapping

The article doesn't say exactly when the P6M's were scrapped, just that they were. Any chance that they survived long enough to be momentarily assigned the otherwise unused P-6 designation in the tri-service designations? Carolina wren (talk) 07:17, 29 December 2012 (UTC)

I dont think so, according to various sources the P-6 designation was not used at the request of the Navy, assumed to avoid confusion with the P6M although I suspect they had all gone by 1962 having been grounded in 1959. MilborneOne (talk) 12:24, 29 December 2012 (UTC)

Another of Sparky's favourites, it seems

So, removed his delusional idea that the aircraft could carry a 30,000 pound bombload since a cursory glance at the empty weight and loaded weight shows that if it carried 30,000 pounds of stores then it didn't carry fuel. Globalsecurity gives the bombload as a more sane 4,000 pounds. Herr Gruber (talk) 16:33, 9 March 2013 (UTC)

No doubt that was actually 30,000 pounds of "Gavins"... - The Bushranger _{One ping only} 16:38, 9 March 2013 (UTC)

What were the likely targets for this aircraft and, unless any of them were area bombing on land, why would it ever need such a massive bombload? The requirement date of 1951 makes carrying heavyweight first-gen nukes a little unlikely. Was this ever considered as a carrier for early H bombs, like the Mk 17? Where is the bomb carriage? A mega-capacity might just about make sense as a H bomber of this date if it's in one huge centre-line bay, but not if it's distributed or above the waterline. Andy Dingley (talk) 16:42, 9 March 2013 (UTC)

Pretty sure Herr Gruber had the right idea here - there's precisely zero logic here, just that "SeaMasters Uber Alles" from Sparky that wormed its way in here. If you haven't heard of him yet, do a web search for "Sparky" and "Gavin". Just remember, this rabbit hole goes deep... - The Bushranger _{One ping only} 16:55, 9 March 2013 (UTC)

Finding out where it put bombs is hard and the best I could find was a model:

http://data6.primeportal.net/models/mike_maynard/p6m_seamaster/images/p6m_seamaster_01_of_16.jpg

Looks like a modular bay at the rear of the flat portion of the hull. You have to remember a mega-payload is very problematic given it's about the size of a B-47 (bombload of 25,000lbs) and the B-47 doesn't have to float. Herr Gruber (talk) 16:58, 9 March 2013 (UTC)

Wasn't this Martin's rotating bay? But was it one on the centreline, or two abreast? Andy Dingley (talk) 17:12, 9 March 2013 (UTC)

Ah, here we go, here's one with the in-flight buddy refueling gear fitted.

http://www.combatreform.org/p6minflightrefuelpack.jpg

That bomb bay tray would fit into the same slot. Just the one. Feels dirty using a link to Sparky's site, but at least it's to prove he's wrong. Herr Gruber (talk) 17:18, 9 March 2013 (UTC)

Looking at the declassified information on the aircraft the bomb loads you 'corrected' were not delusional, the max load weight was incorrect. I've taken information from the US Military documents related to the production P6M-2 and updated the specifications for the aircraft. The largest ordinance set carried by this aircraft actually weighed 30,450 lbs. (15 x MK25 Mod 2 Naval Mines, they're about 2,000 lbs each.) There is a good amount of variation between the two prototypes and the final production aircraft. The aircraft according to the documents would not normally carry a full, but ample, tank of fuel but could carry nearly a full tank even with the largest ordinance option. Doing so would place it very close to its maximum takeoff weight. This aircraft was designed to carry sea mines to bottle up the Russian fleet, handle aerial reconnaissance, sub hunt, and was to be the USN answer to dropping nukes on our enemies. The documents list two specific nuclear variants (Mk91 & Mk28) that were to be carried by this aircraft, and could have carried others including a nuclear depth charge for use in sub hunting operations. The large bomb load was required for the Mark 36 and Mark 25 mine deployment operations. Fleets of these aircraft were to rapidly deploy from water basing to the 'bottlenecks' the Russian fleet had to pass through and close them off. If they decided to use these for conventional means... The large useful loads could prove effective dropping large amounts of conventional ordinance and returning to a mobile tender just offshore. Basing close to shore would make the resupply and return runs very short and these aircraft could carry a surprisingly large load.Cobaltclass 02:35, 26 September 2015 (UTC)

Were it not for the minor issue that the mines disintegrated when they hit the water and the whole idea is something out of an episode of Thunderbirds. And then someone invented the ICBM and everyone was like "oh, right, that does make a lot more sense than building dozens of P6M action playsets." Also, could you give us an actual citation for those figures? They don't mean a lot if they're not published, since anyone can make up a bunch of numbers and say they're declassified figures. Herr Gruber (talk) 11:43, 22 October 2015 (UTC)

Also this video ends with one laying mines, as well as an explanation of why the plane wasn't exactly suited to the minelaying role. Herr Gruber (talk) 17:26, 9 March 2013 (UTC)

Taxying

AIUI, the P6M was a pure flying boat rather than an amphibian. Like most of such, it came out of the water on a dolly. However, owing to its large size and deep draught, it was too deep to pull out with the usual tractors. The solution was a floating dolly, with attached camels, and for the aircraft's own engines to be used to taxi up the ramp. Andy Dingley (talk) 21:26, 9 March 2013 (UTC)

I've seen it called a beaching cradle.

As for taxiing, I've seen P6M said to taxi; I always understood any low-speed operations to be taxiing, since the term's been applied to amphibians. TREKphiler ^{any time you're ready, Uhura} 01:41, 10 March 2013 (UTC)

I just found it a little misleading, it implied it had come up a boat ramp by itself directly from the water. Which, like I said, wouldn't really be possible since you'd have to stop and attach the beaching cradle first. Herr Gruber (talk) 08:58, 10 March 2013 (UTC)

Number built

Infobox says 12 were built, while the body of the article says 2 prototypes, 6 pre-production models and 8 production models. Obviously both can't be right, so how many were there? 12 or 16? 207.98.198.84 (talk) 06:06, 24 June 2015 (UTC)