Hs 293 – First Guided Anti-Ship Missile

293

Another guided air-to-surface weapon in the arsenal of modern air forces is the guided anti-ship missile. The first such weapon was also developed (by Henschel) and deployed by the Nazi Luftwaffe. It was Hs 293 – a radio controlled glide bomb with a rocket engine slung underneath it.

Unlike Fritz X designed to be used against heavily armored targets, Hs 293 was intended to be used against merchant ships and lightly-armored vessels. This allowed the bomb to be used from a lower altitude and at an increased range compared to a gravity bomb such as Fritz X.

The weapon consisted of a modified standard 500 kilogram SC 500 bomb with an added “Kopfring” device on the nose for maritime use – to help ensure a relatively perpendicular axis of impact.

The bomb had a thin metal shell and a high explosive charge inside and was equipped with a rocket engine beneath its body, a pair of aileron-fitted wings, and the receiving FuG 230 component of the Kehl-Straßburg guidance and control system – the same as used in Fritz X gravity bomb.

Five colored flares were attached to the rear of the weapon to make it visible at a distance to the operator. During night operations flashing lights instead of flares were used.

A major drawback of Hs 293 was that after it was launched, the bomber had to fly in a straight and level path at a set altitude and speed parallel to the target so as to be able to maintain a slant line of sight and could not maneuver to evade attacking fighters without aborting the attack.

The Hs 293 was carried on Heinkel He 111, Heinkel He 177, Focke-Wulf Fw 200, and Dornier Do 217 planes. However, only the He 177, certain variants of the Fw 200 and the Do 217 used the Hs 293 operationally in combat.

Which was quite successful, actually. On August 25, 1943, an Hs 293 was used in the first successful attack by a guided missile, striking the sloop HMS Bideford; however, as the warhead did not detonate, the damage was minimal.

On August 27, the sinking of the British sloop HMS Egret by a squadron of 18 Dornier Do 217 carrying Hs 293s led to anti-U-boat patrols in the Bay of Biscay being temporarily suspended. On November 26, an Hs 293 sank the troop transport HMT Rohna killing over 1,000 personnel.

Although designed for use against ships, the missile was (unsuccessfully) used in Normandy in early August 1944 to attack bridges over the River See and River Selume. One bridge was slightly damaged for the loss of six of the attacking aircraft (due to heavy anti-aircraft fire and fighter cover).

The Allies put considerable effort into developing devices which jammed the radio link between Kehl transmitter and Straßburg receiver. Jammers aboard U.S. Navy destroyer escorts were ineffective at first, as the frequencies selected for jamming were incorrect.

However, later Allied attempts at countermeasures were much more successful. British Navy began to deploy its Type 650 transmitter which employed a different approach to interfering with the FuG 203/230 radio link, by jamming the Straßburg receiver’s intermediate frequency section, which operated at a 3 MHz frequency.

This one worked, because the transmitter operator now did not have to try to find which of the eighteen selected Kehl-Straßburg command frequencies were in use and then manually tune the jamming transmitter to one of them. The Type 650 automatically defeated the receiver, regardless which radio frequency had been selected for a missile.

By the time of invasion of Normandy and the Southern France, the Allies developed even more efficient countermeasures. These included AIL’s Type MAS jammer, which employed sophisticated signals to defeat the Kehl transmission and to take over command of the Hs 293, steering it into the sea via a sequence of right-turn commands. Which made missile attacks all but futile.

Fritz X – First Guided Bomb

FX

Today, air forces of all major nations are equipped with guided bombs (precision-guided munitions or “smart bombs”). The first such weapon – FX 1400 (better known as Fritz X) – was developed (by Ruhrstahl), deployed and successfully used in combat by the Luftwaffe of Nazi Germany.

Although Fritz X was first deployed on 21 July 1943 in a raid on Augusta harbor in Sicily (then invaded by the Allies), its biggest success was achieved on September 9th of the same year.

After Pietro Badoglio publicly announced the Italian armistice with the Allies on 8 September 1943, the Italian fleet had steamed out from La Spezia and headed to Tunisia. To prevent the ships from falling into Allied hands, six Do 217K-2s from III. Gruppe of Kampfgeschwader 100 took off, each carrying a single Fritz X.

The Italian battleship Roma, flagship of the Italian fleet, received two hits and one near miss, and sank after her magazines exploded. 1,393 men, including Admiral Carlo Bergamini, died. Her sister ship, Italia, was also seriously damaged but reached Tunisia.

Fritz X was a further development of the PC 1400 armor-piercing high-explosive bomb. It was a penetration weapon intended to be used against heavily armored targets such as heavy cruisers and battleships. When working properly, the missile was able to pierce 130 mm armor.

Fritz-X was steered by the bombardier in the launching aircraft (Dornier Do 217K-2 medium bomber) over a radio link between the aircraft’s Kehl transmitter and the weapon’s Straßburg receiver.

The bombardier had to be able to see the target at all times, so the Fritz-X bomb had a flare in the tail so it could be seen from the controlling aircraft for its guidance system to control it properly. A skilled bombardier could manage to guide half of the dropped bombs to within a 15 m radius of the aiming point, and achieve about 90% hit within a 30 m radius.

The control system used for Fritz X relied on radio contact between the bomb and the guidance unit, and was susceptible to electronic countermeasures. After the initial attacks in August 1943 the Allies went to considerable effort to develop jamming devices.

These were first deployed in late September 1943 and by the time of the Normandy landings, a combination of Allied air supremacy (keeping the Luftwaffe’s bombers at bay) and ship-mounted jammers meant Fritz X had no significant effect on the invasion fleet.

First Operational Aircraft Ejection Seat

EjectionNowadays, an ejection seat is a standard feature on just about any military aircraft (with the exception of some cargo ones). Interestingly enough, the modern layout for an ejection seat was first proposed not by someone associated with a major air power (e.g. Germany or Britain), but by a Romanian inventor Anastase Dragomir in the late 1920s.

The design, featuring a parachuted cell (a dischargeable chair from an aircraft), was successfully tested on 25 August 1929 at the Paris-Orly Airport near Paris and in October 1929 at Băneasa, near Bucharest.

However, the first aircraft to be fitted with such a system was the Heinkel He 280 prototype jet-engined fighter in 1940 (the first turbojet-powered fighter aircraft in the world). Unfortunately, persistent problems with its engines (initially with Heinkel and subsequently with BMW designs), led to it being passed over in favor of the now-famous Me-262.

It was one of the He 280 test pilots – Helmut Schenk – who became the first person in the world to escape from a troubled aircraft with an ejection seat on 13 January 1942 after his control surfaces iced up and became inoperative.

The first operational aircraft to provide ejection seats for the crew was (not surprisingly) also the one developed by Heinkel. It was He 219 Uhu (“Owl”) – the first dedicated night fighter – which was deployed in June 1943.

The first operational jet aircraft to be equipped with the ejection seat (of a new type – fired with explosive cartridge) was also the German WW2 design – and also by Heinkel. The Volksjäger (“People’s Fighter”) He 162 Spatz (“Sparrow”) which was quite a Wunderwaffe itself.

The only aircraft not developed by Heinkel that was equipped with an ejection seat was Dornier Do 335 Pfeil (“Arrow”) heavy fighter. Like He 162, it had a design feature that made the ejection seat a necessity.

Do 335 had a rear-mounted engine (of the twin engines powering the aircraft) powering a pusher propeller located at the aft end of the fuselage and thus presenting a hazard to a normal “bailout” escape.

He 162 had its jet engine (BMW 003) mounted on top of its fuselage behind the cockpit which also made normal “bailout” a very risky endeavor (to put it mildly).

Tiger I – the First Main Battle Tank

Tiger

Although when it was deployed to Panzerwaffe units of Wehrmacht and Waffen-SS in 1942, Tiger I tank (PzKpfw VI Ausf. H) was classified a heavy tank, most modern main battle tanks essentially follow a very similar design – and definitely the designed principles pioneered by Tiger I with its focus on thick armor and a superior firepower.

Tiger I had a total weight of about 54 tons (typical weight of a modern main battle tank) and boasted 120mm frontal armor (penetrable by most Allied guns only at a very close range) and an extremely powerful 88mm KwK 36 gun – considered probably the best tank gun of World War II.

The KwK 36 was very accurate and high-powered, and its high muzzle velocity produced a very flat trajectory. This allowed its gunners a higher margin of error in estimating range and the sighting system of the gun resulted in excellent firing accuracy.

The Tiger I had frontal hull armor 120 mm thick, frontal turret armor of 100 mm and a 120 mm thick gun mantlet. It had 60 mm thick hull side plates and 80 mm armor on the side superstructure/sponsons, while turret sides and rear were 80 mm. The top and bottom armor was 25 mm thick; from March 1944, the turret roof was thickened to 40 mm.

The M4 Sherman’s 75 mm gun (or 76mm gun of Soviet T-34 and KV-1 tanks) would not penetrate the Tiger frontally at any range, and needed to be within 100 m to achieve a side penetration against the 80 mm upper hull superstructure. Consequently, it is no surprise that Tiger I achieved a kill ratio considerably higher than 10:1 against these tanks on a battlefield.

The tank’s weight significantly limited its use of bridges. For this reason, the Tiger was built with watertight hatches and a snorkel device that allowed it to cross water obstacles four meters deep.

Although from a technical point of view it was superior to its contemporaries, the low number produced, shortages in qualified crew and the considerable fuel requirement in a context of ever shrinking resources prevented the Tiger I from having a real impact on the war.

 

Sturmgeschütz III – First Mass-Produced Self-Propelled Artillery

StuG_III_Ausf._G

Self-propelled artillery is an important armored component of every modern army. However, it was not always that way. In fact, at the outbreak of World War II, virtually all artillery was still being moved around by artillery tractors or horses. With one notable exception – the Wehrmacht.

German military doctrine of blitzkrieg required mobile fire support for armored units (tanks and motorized infantry). Which could be provided only by self-propelled guns adequately protected from artillery fire on the battlefield (as they were supposed to provide both indirect and direct fire support).

This requirement gave rise to the development of Sturmgeschütz III (StuG III) – the first mass-produced assault gun (“Sturmgeschütz” means exactly that). And essentially the first mass-produced self-propelled artillery. In fact, StuG III was Germany’s second most-produced armored fighting vehicle during World War II after the Sd.Kfz. 251 armored personnel carrier.

It was also the first operational self-propelled artillery piece that carried their main armament in a fully enclosed and fully-armored casemate – the standard feature of most subsequent designs.

StuG III was built on the chassis of the proven Panzer III tank, replacing the turret with an armored, fixed superstructure mounting a more powerful gun. Initially intended as a mobile assault gun for direct-fire support for infantry, the StuG III was continually modified, and much like the later Jagdpanzer, was employed as a tank destroyer.

Overall, the Sturmgeschütz III series assault guns proved very successful and served on all fronts as assault guns and tank destroyers. Because of their low silhouette, StuG IIIs were easy to camouflage and were difficult targets. Its design proved to be so efficient that Syrian StuG IIIs were in use until the Six-Day War of 1967 (!), and possibly even later.

Sd.Kfz. 251 – First Armored Personnel Carrier

251In every modern army, all infantry is motorized. In other words, it is transported (both on, to and from the battlefield) in a specially designed motor vehicles – armored personnel carriers (APC).

And the first mass-produced and operationally deployed (in huge numbers – over 15,000 were produced) armored personnel carrier was the famous half-track Sonderkraftfahrzeug 251 (“Special Purpose Vehicle” 251) better known by the acronym Sd.Kfz. 251 or by the name of the company that designed it – Hanomag.

Interestingly enough, the first ever APC (actually, ersatz-APC) was fielded by the German Army as well – in World War I. The first mechanized infantry in the military history were assault teams mounted on German A7V tanks. The vehicles were extra-large to let them carry sizeable assault teams and would regularly carry infantry on board in addition to their already large crews that were trained as storm troopers.

All machine-gun-armed A7V tanks carried two small flame throwers for their dismounts to use. A7V tank would often carry a second officer to lead the assault team.

Development and deployment of Sd.Kfz. 251 was the inevitable result of the adoption of blitzkrieg strategy by the Wehrmacht in mid-1930’s. This strategy required lightning-fast, massive attacks by tanks and assault guns supported by infantry that had to (1) keep up with tanks on just about any terrain and (2) be protected from rifle and light machine gun fire and from mortar and artillery shell fragments.

Which could be accomplished only by mounting infantry on armored personnel carriers thus creating motorized infantry (called Panzergrenadier units in Wehrmacht and Waffen-SS).

Thus Sd.Kfz. 251 was designed to transport a single squad of ten Panzergrenadiers to the battlefield protected from the abovementioned enemy fire. In addition, the standard mounting of at least one (often two) MG 34 or MG 42 machine gun allowed the vehicle to provide suppressive fire for the rifle squad both while they dismounted and in combat.

Like all APC fielded in World War II, Sd.Kfz. 251 had an open-top design which provided greater situational awareness and faster egress by the infantry, as well as the ability to throw grenades and fire over the top of the fighting compartment as necessary while remaining under good horizontal cover.

The obvious downside was a major vulnerability to all types of plunging fire; this included indirect fire from mortars and field artillery, as well as small arms fire from higher elevated positions, lobbed hand grenades, even Molotov cocktails, and strafing by enemy aircraft.

There were four main model modifications (A through D), which formed the basis for at least 22 variants, which included a multiple 280- or 320-mm rocket launcher; 81 mm mortar carrier; communications vehicle, fitted with extra radio equipment for command; gun-towing tractor; assault engineer vehicle; armored ambulance; assault gun (equipped with a 75mm low velocity cannon or a 37mm cannon); flamethrower carrier; anti-aircraft vehicle equipped with a 20mm AA gun; tank destroyer equipped with a highly-effective 75mm PaK 40 anti-tank gun, etc.

However, because the German economy could not produce adequate numbers of its Sd.Kfz. 251, barely a quarter or a third of the infantry in Panzer or Panzergrenadier divisions were mechanized, except in a few favored formations. The rest were moved by truck (and on the battlefields had to mount tanks – just like their Soviet counterparts who had virtually no APCs at all).

The only army whose infantry was fully equipped with APCs was the US Army that used M2 and M3 half-trucks similar in design to Sd.Kfz. 251.