renhanxue

If you were indecisive about buying a Draken, this 1960 Australian evaluation of the J 35B might help you make your decision (does breaking the sound barrier in level flight with dry thrust only sound appealing to you?). Relevant documents start on page 74, report from the test pilot starts on page 87. The same file also contains at least a partial eval of the Mirage III.

That's just the ready rack.

Topmost is the strv m/42. The rest are variants of Landsverk's Lansen proposal, an attempt in 1949-1951 to sell, on the international market, a 20-25 ton tank that in most respects was on par with a tricked out Sherman. Naturally, everyone just bought surplus Shermans (or Centurions) instead and it was never built. I don't really see what's weird about the ammo rack placement though, are you talking about the stuff in the turret bustle? Why is that weird?

You like the Lansen? Have some more! I posted this on SA originally but it deserves getting spread. Someone dug up, digitized and YouTubed a 1975 Super8 recording from the Swedish air force's 6th wing/2nd strike squadron. It's cold war as fuck. In those days, men were men, pilots had ridiculous mustaches, safety regulations about low altitude flying were still a thing for pansies, the squadron still flew the Lansen (one of the last squadrons to do so; the strike version left service for good in 1978), and dumb bombs were still a valid weapon choice against naval targets. The original film was mute, so all sounds have been added in postproduction. Highlights (but you should really watch the whole thing): 2:00 if you want to skip the briefing and the mustaches 4:00 actual low altitude flying starts 6:20 bombing run starts 8:10 and onwards to the end has some pretty cool low altitude shots, with the shadow of the plane occasionally giving an idea of how low they're flying

Proceedings of Symposium on human engineering aspects of main battle tank design, as held at Shrivenham in April 1969.

Does anyone mind if I post some contextless tank porn? No? I photoed a several decimeters tall stack of photographs at the national archives this summer and I have no idea what to do with them. Should I just turn tanks.mod16.org into a photoblog in the style of Yuri Pasholok? In the meantime, have some samples: People on tanks: Strv m/42, Stockholm, April 1944. Strv m/39, Strängnäs, 1942. Strv m/41, Stockholm, 1943. Strv m/42, 1944. People pretty far above tanks: Pvkv m/43 and Saab B17, June 1947. Strv m/42 and Saab A21.

I'm pretty sure that in the torsion bar case the lever that connects the bar and the road wheel is called a "swing arm". I might have to write something about hydraulic suspension now, for those special snowflake tanks.

le epic meme face XD Have a copy of a post I made a while ago: Here are some words about the JA 37 intercepts of the SR-71 during the 80's. Most of the text is translated or adapted from the book "System 37 Viggen" (Flyghistorisk revy, 2009). The JA 37 tactics development unit got started quite early on with working on a mission profile for intercepting targets at very high altitudes. The targets considered were the SR-71 Blackbird and the MiG-25 Foxbat; both types were capable of mach 3 at altitudes above 20,000 meters (65,000 ft). Since the Viggen obviously wasn't fast enough to catch up to the target, the profile they came up with involved the intercepting aircraft meeting the target on a directly opposite course, with intercept vectors and combat control provided by ground-based installations over datalink and/or regular speech radio (in Swedish terminology, the air combat control system was known as "Stril", portmanteu for "Stridsledning och luftbevakning", which means something like "combat control and aerial surveillance"). This meant the JA 37's PS-46 radar would be supported by the ground-based Stril ones, since the intercepting aircraft couldn't catch the target on its own radar in time to climb and accelerate to intercept. The tactics and armament systems were developed in the JA 37 systems simulator at Saab, with the simulator connected to Stril. For obvious reasons there were no opportunities to practice against our own aircraft in reality. The mission profile started with acceleration in level flight to mach 1.35 at 8000 meters (~26,000 ft). Then the nose was raised to 3-5 degrees above the horizon in order to climb while accelerating further. The maximum altitude was kept within the 16000 meter envelope ceiling mandated during training. The USAF SR-71 recon missions were commonly known as the "Baltic Express". Usually, the SR-71's entered the Baltic at an altitude of about 21,500 meters (70,000 ft) about 80 km south of Copenhagen, accelerated to mach 2.98-3.0, continued eastwards and then northwards along the coasts of East Germany, Poland and the Baltic states, followed by a left turn westward, crossing the Baltic sea to the Swedish side just south of Åland, then another left turn southward and flying through the narrow corridor of international airspace between Öland and Gotland. Initially the left turn westward south of Åland was so wide that the SR-71's ended up violating Swedish air space, which led to a diplomatic protest which caused the SR-71's to slow down to mach 2.54 during the turn before accelerating to mach 3 again on the southbound leg. Between 1977 and 1988, 322 such missions were flown; in a few cases the mission was also flown in reverse. Map of a typical SR-71 flight (note the times - wallclock time - noted along the flight path, the violation of Swedish airspace near the top and the Soviets running circles in the top right): The intercepts would typically be done around the place that says "0910" on the route, or slightly north of it. Simulator training on the mission profile started in Norrköping at the 13th air wing (one of the first wings to receive JA 37's; it had been equipped with them during 1981) for both pilots and air combat controllers. You couldn't know who ended up getting the intercept, so everyone was trained. The first real intercept opportunity came on October 26th 1982, when a pair of Viggens encountered an SR-71 for the first time. One of the pilots tells the story: The second intercept occurred a week later, on November 1st, 1982, with another pair of Viggens from the 13th air wing: Another intercept worth mentioning involved a group of three Viggens and occurred on January 9th, 1986. The group started southward from Norrköping with the intention of intercept training, but immediately after takeoff it was ordered to prepare to intercept a target that was suspected to be a SR-71. The group climbed to 8000 meters on a southeasterly course and then turned northward over the Baltic sea southeast of Västervik, forming up in a column. At this point the JA 37 had been equipped with the fighter-to-fighter data link, so the Viggens could share targeting data with each other, not just with the ground. All three aircraft conducted a simulated missile firing independently. The intercept started at 13:14 local time and was complete at 13:25; the intercept point was about 50 km west of Visby, on the island of Gotland. The target was flying at an altitude of 21,500 meters at mach 2.9 and as usual attempted to jam the PS-46 radar. The Viggen group had had plenty of time to climb and accelerate, so when the lead and the second aircraft had passed the target the flight lead called to continue at maximum speed since the mach number at that point was around 2.0. The third aircraft did not reply, though, so the leader asked for his status. The answer was "I'm gliding". The third aircraft had suffered a high temperature engine stall. The engine had stalled briefly, the exhaust temperature rose and the warning light "EXHAUST TEMP." was lit. The pilot followed procedure and turned the engine off, and then restarted it when he descended below 12,000 meters. Having the engine stall at that kind of altitude was very scary since without bleed air from the engine, the cabin would lose pressurization within minutes. The entire group exceeded 18,000 meters of altitude during the intercept. The fighter version of the Viggen really wasn't what you'd normally consider well suited to high speed/high altitude intercepts. It had fixed engine intakes, which meant it couldn't exceed mach 2 and it ordinarily had a ceiling of 16,000 meters, where its performance was decent for its time but not really comparable to that of purpose-built high altitude interceptors. Flying it at such high altitudes could be risky; the engine and the intakes were operating at the very edge of their capabilities and there was a passage in the flight manual that cautioned against "hammershocks" in the intakes that could possibly tear the aircraft apart if the engine stalled at high speed and high altitude. Nevertheless, in many cases it succeeded with intercepting even such a difficult target as the SR-71 anyway (over 50 successful intercepts recorded by the air force during the 1982-1988 period). The success can be attributed in part to the predictable flight paths but also to the aircraft's excellent data links, which were quite exceptional for its time and made it a lot more capable interceptor than it would otherwise be. Catching up to the target is one thing, but you also need to know where to find it.

Got penetration figures (or, rather, distances) for all Swedish anti-tank weapons as of 1970 declassified today. Enjoy: http://imgur.com/a/RExzB 105 mm APDS L28 and L52A1 for the L7 gun (both the standard variant and the longer one mounted on the S-tank) are included.

That's someone who cut out the juicy parts of this.

The Swedish pz38t was actually in service into the early 1960's. :V Then they reused the chassis to make APC's (a temporary solution that lasted less than 10 years) and the turrets to make fixed fortifications at airfields and the like. I guess the 37mm could potentially be useful against trucks and things like BMD's even in the late cold war, maybe...? There were several attempts by the army to just snag a bunch of surplus Shermans (they didn't really like the strv m/42 much, too unreliable) but it never came to anything. Instead political wrangling and a lot of debating about what the hell you're supposed to use tanks for now that HEAT rounds are such of a thing delayed actually buying something decent until 1951, when they finally went with the Centurion, mainly because it was there and could be delivered immediately (important, since they had delayed so much previously). I can't confirm this with first hand sources, but I strongly suspect that a big reason they didn't buy anything after the war was that the procurement during the war was also a clusterfuck. They had to go with what was available, what was available wasn't very good and there was a lot of catfighting internally about whose fault it all was that it took so long to get tanks that were long obsolete by the time they had worked the bugs out of them. I think the army really wanted to sit down, test a bunch of foreign tanks (which they did) and figure out what the hell was going on before they committed to anything new.

The gunnery manual says: "In general, main gun and fixed machine gun fire (fixed machine guns exist on strv 103 only) shall be opened from a stationary tank. With the strv 101/102 (Centurion) main gun, fire may be opened on the move at targets up to 800 meters away, for example if you unexpectedly come upon an enemy or during the storming of a position. With strv 103 main gun and fixed machine guns, fire may be opened on the move at targets up to 200 m away, provided that the ground is even and that there are terrain features behind the target (such as a treeline or a backslope) that can catch any misses. With the turret machine guns on the strv 101/102 and the commander's machine gun on the strv 103, fire may be opened both from a stationary tank and on the move." Further on, it says: "The enemy is expected to use large numbers of AFV's against us. Therefore, we must fight in such a way that we can win even if we're outnumbered. This requires both firing fast, in order to increase the likelihood of disabling enemy targets, and firing well, in order to disable the enemy before he disables us while using the least possible amount of ammunition." Then it emphasizes this even more, and has an outlined box with some particularly important maxims: "In tank duels, the tank that fires first will win four times out of five. The tank that gets the first hit is four times more likely to win. All tank fire shall aspire both to hit with the first round, and to disable the target with the first hit. A well trained tank crew shall be able to hit with their first round and disable the target within 10 seconds of opening fire." In other words, the manual heavily emphasizes well aimed fire and discourages firing on the move. Firing on the move is something you may do under exceptional circumstances when surprised by the enemy, or at extremely short distances, or possibly in order to attempt to keep ATGM crews and the like suppressed.

In case anyone was wondering what this is, it's the ballistic tables for the 12cm Rheinmetall gun on the Swedish Leopard 2's.

One of these days I will write a long ass post about how the Swedish army really thought the strv 103 was a tank and used it as a tank, and that the "shoot and drive backwards quickly in the forest" thing is a History Channel myth. I'll need to quote a bunch of field manuals in support of my thesis, so I've been acquiring some through various channels and scanning them. Since you gentlemen are some truly arcane nerds, I figure some of you might appreciate the illustrations at least, so here you go: Tank gunnery manual, 1979 edition Field manual for tank platoons, 1974 edition

Right. The designation for the ZF gearbox for the m/42 was 6 EV 75, IIRC. Meanwhile the army studied captured T-34's in Finland and was like "well, clearly a purely mechanical gearbox is possible, can we please get one like on the T-34 instead of these hydraulic and electromagnetic things?". Then Volvo eventually designed such a gearbox (which I suspect was inspired by the one on the T-34) called VL 420 which was used on the pvkv m/43 TD (same chassis), and a few years after the war all the remaining m/42's with ZF's electromagnetic shit were also refitted with the VL 420, ending the ZF design's miserable existence for good.

The Swedish army was fooled by the rumours of GERMAN ENGINEERING QUALITY too and bought a ZF electromechanical gearbox for the strv m/42, primarily because it was light and the army was desperately trying to save a few kilograms, and because there were no Swedish tanks heavier than 10 tons at the time and there was no time to develop a new gearbox domestically. The thing turned out to be so fucking unreliable that the army suspected sabotage and started an investigative commission which asked some very pointed questions to the ordnance department (who had ordered it) and Landsverk (who built the tank) and sent an investigator to Germany to see if prisoners of war were fucking shit up. It took years and three or four iterations to sort the problems out and bringing the gearbox up to an acceptable level of reliability. In October 1944 the 3rd Armored Regiment at Strängnäs reported that 51 out of 89 strv m/42's with the ZF gearbox were unserviceable. Many of the moving parts in the gearbox were found to be made of materials completely inappropriate to the conditions they were supposed to work in, and tended to break or overheat after tens of kilometers on the road. Eventually the problem was mostly solved by replacing parts with Swedish-manufactured ones of higher quality and adjusting the lubrication several times, but the problem wasn't really solved until late 1944/early 1945. (mostly) Actual quotes from the sales engineers: - "oh we're using it in our SIXTY TON TIGER" - "the magnetic plates are basically eternal, they'll last forever" (actually made of garbage quality steel full of dross, broke early and often) - "electromagnetic gearboxes are the future, within three or four years they'll be the only gearbox used on new tanks" (said in 1942) - "Sweden is the only country we're exporting these to, the design is actually classified you know" - "well, we can't leave any guarantees that our gearboxes will work a fixed number of kilometers or anything, but we're convinced you'll be satisified with them" - "we promise on our good reputation as a high quality engineering firm that these gearboxes will be good" Fucking scammers.

Not really Swedish per se and I don't think there's anything new here but anyway, have some datasheets and drawings: http://tanks.mod16.org/pdf/Centurion%20mk%2010%20datasheet%20and%20drawings.pdf

Some Russian guy emailed and asked me if I had test reports on the effectiveness of "chain armor", and in fact, I did, so here's a translation of one: http://tanks.mod16.org/2015/07/12/ballistic-tests-with-heat-rounds-against-chain-armor/

There were such plans for Norway too, yes, and more realistic ones too. The Danish plan was more or less cancelled when some boring dudes started asking complicated questions such as "how are we going to conduct an amphibious landing without any landing craft?". The plan involved fishing craft and when they exercised it on the Swedish coast it took for fucking ever for the infantry to get ashore. It would have been impossible if there had been the slightest resistance. A PDF in Swedish about the Danish plan: http://www.krigsmyter.nu/raddadanmark.pdf

I think the US has gone about introducing women in the armed forces in the most backwards way possible, really. Treat other people like people and don't make a big deal about it and it won't become a big deal. In the Swedish army, men and women often share showers/other hygienic facilities, especially in the field. They almost always share tents in the field. Sometimes they even share sleeping bags in the field. At least one of the Swedish submarine crews has one (1) female crew member - take one guess as to whether she gets any special treatment/facilities of her own on board a tiny ass littoral sub. The physical/psychological tests/requirements are the same for men and women; as of last year no woman had finished ranger school (yet - there's been good attempts but they've been forced to abort for various reasons). If you can't separate private and professional life and treat your fellow soldiers like people like a decent human being, you have problems that you shouldn't blame on women.

Chillin': Also, I found the holy grail: That's a blueprint for the Krv hull that was actually built. We previously believed all blueprints had been burned back in 1958 but apparently some seem to have survived. (click for bigger images)

I don't know but since the guy was a war correspondent and the national archives library has a copy I'd figure it's nonfiction. I'll try to remember to check it out on monday.

"This item is not available online ( Limited - search only) due to copyright restrictions." I can tell you right now though that it's not a Swedish book by a Swedish author. It's a Swedish translation of a presumably British book, The Tanks, by a man named Philip Gibbs (most likely this guy). If I Google "Philip Gibbs the tanks" all that comes up is this Swedish translation, which is weird, but presumably the English original should exist somewhere. I could also go look at it in the national archives library (they do have a copy) if you want, but I don't have time to give you a full translation.

Don't try to google translate that, almost every single line is an obscure military abbreviation of some kind. I'll see about giving you a translated summary.

Did someone say Draken?