20th+: September 2019

Communication, Surveillance - PrTe >> .

The dawn of instant global communication can be traced back to entrepreneur Cyrus West Field and his long-shot experiment to link the United States and Europe by telegraph in the 1850s.

Polyethylene, radar, and submarine cables ..

The underwater web > .

modern Space X's Starlink and the Military - CoCa > .

London's Old Phone Boxes > .

Wednesday, September 25, 2019

D-Day innovations

Hobart's Funnies: D-Day's Weird and Wonderful Tanks - Side > .

Lies and Deceptions that made D-Day possible - IWM > .

June 6th 1944 - The Light of Dawn 1 - Doc > .

Hypothetical modern D-Day invasion - Binkov > .

Higgins Boat - Ugly Little Boat That Won WW2 - HH > .

D-Day trickery > .

Operation Bodyguard: Crazy (Successful) Plan to Fool Hitler Before D-Day - Mega > .

Analog & Digital Computing ↠

1. TIDE-PREDICTION MACHINE

In 1942, British mathematician Arthur Thomas Doodson had begun working on existing models of tide-prediction machines - essentially mechanised calculators that could reveal tidal patterns. In 1944, using his specially modified machine >, Doodson identified the exact time the landings should take place (H-Hour) and that D-Day should fall between 5 and 7 June.

2. LANDING CRAFT
Crocodiles, Donald Duck, Landing Craft ..

The development of specialised landing craft had begun early in the war. D-Day vessels ranged from tiny Assault Landing Craft to huge Landing Ships. Other landing craft were fitted with guns or rockets. There was even a 'Landing Barge, Kitchen'. Equipment could be brought directly onto the beaches, providing a short-term solution to the problem of securing the harbours and ports needed for the immediate build-up of men and materiel.

3. HORSA GLIDERS
Gliders ..

Horsa gliders were first produced in 1942 and made significant contributions to airborne assaults throughout the latter part of the Second World War. On D-Day, these gliders were used on an unprecedented scale to transport troops and supplies to Normandy. They were towed by transport or bomber aircraft before gliding into the landing zone, where supplies could be retrieved. Gliders transported heavier equipment that could not be delivered via parachute drops or when using larger transport aircraft was not possible. The hinged nose and removable tail section allowed cargo to be unloaded relatively easily without damaging the overall structure. But gliders were flimsy – constructed mainly of wood and fabric – and were difficult to operate. They would often violently break apart on landing, especially during improvised or crash landings.

4. 'HOBART'S FUNNIES' AND AVRES
Crocodiles, Donald Duck, Landing Craft ..
Hobart's Funnies ..
These unusual vehicles played an important role on D-Day and throughout the Battle of Normandy. The failed raid at Dieppe in August 1942 exposed how difficult it was to land armoured vehicles during an amphibious invasion and to break through German coastal defences with insufficient armoured support. As a result, armoured vehicles were designed to perform specialist tasks and reinforce ground troops on D-Day. These vehicles were nicknamed 'Hobart's Funnies' after their inventor, Major-General Sir Percy Hobart. They include the Duplex Drive (DD) 'swimming' tank; the 'Crocodile' flamethrower tank and the 'Crab' mine-clearing flail tank. Although the Funnies had been used in simulation and training exercises, they had not been tested in combat until D-Day. Modified vehicles known as AVREs (Armoured Vehicle Royal Engineer) were created by adding specialised devices to tanks. One example, the 'bobbin' carpet layer tank, laid reinforced matting on sandy beaches so other vehicles could drive across the soft surface.

5. MULBERRY HARBOURS
Mulberry Harbours ..

Mulberry Harbours WW2: Disaster at Dieppe led to D-Day success - IWM > .
After D-Day, the Allies needed to continually build up reinforcements of men and supplies in Normandy to sustain the invasion's momentum. Previous experience taught the Allies hard but important lessons about the need to secure harbours and ports - harbours to provide protection from bad weather and rough seas, and ports to provide a place to ferry men and cargo. The planners responsible for 'Overlord' proposed creating two artificial harbours - codenamed 'Mulberries' - by sinking outdated ships ('Corncobs') and large concrete structures ('Phoenixes'). Adding floating roadways and piers (codenamed 'Whales') would allow them to use the beachhead as an improvised port.

6. PLUTO

PLUTO - short for 'pipeline under the ocean' - supplied petrol from Britain to Europe via an underwater network of flexible pipes. It gave the Allied forces access to enough petrol to fuel aircraft and vehicles and to sustain the momentum of their advance. Two PLUTO pipelines ran from the Isle of Wight to Port-en-Bessin - the linkup point between Omaha and Gold beaches. Another pipeline was added later, running from Dungeness on the Kent coast to Boulogne in France, and the PLUTO network continued to expand as the Allies advanced across Europe. The 3-inch-wide pipeline was wound around giant floating spools called 'conundrums' - like the one in this photograph - and then unrolled across the Channel.

7. GERMAN DEFENCES
Atlantikwall ..
German Defences ..

When Field Marshal Erwin Rommel was put in charge of German defences in Normandy, he believed that any invasion would come at high tide, when the beachhead was at its narrowest and troops would be vulnerable to German fire for the shortest period of time. He therefore devised a series of obstacles adapted for use under water that would be completely concealed during mid and high tides. The jagged edges of iron 'hedgehogs', pictured above, could tear through the bottom of landing craft. Some were rigged with explosives that would detonate on impact. Round, flat land mines (called 'teller mines' after the German word for 'plate') were attached to wooden posts wedged into the sand and would explode when they came into contact with landing craft. Inland, Rommel also designed a network of large posts fixed vertically into the ground that prevented gliders from landing in open areas. These defences were nicknamed 'Rommel's Asparagus'.

https://www.iwm.org.uk/history/7-clever-innovations-used-on-d-day .

44-6-6 D-Day landings - AFPU ..
Logistics of D-Day ..

D-Day Logistics - Why Did The Allies Pick Normandy? > .

The Logistics of D-Day - Mulberry Harbours - ReEn > .

Directional Wireless Installation

Hoops? > .

https://www.youtube.com/watch?v=sCna-_yZaj4 >

Directional Wireless Installation

https://medium.com/war-is-boring/how-britain-beat-germanys-wwii-magnetic-sea-mines-bfec5558704c

Tuesday, September 24, 2019

Electronics - Technological Advances

How Germany Lost the Radar Race in WW2 - Binkov > . skip ad > .

Why 17 Million Telegrams Are Still Sent Every Year - Half > .
RDF, technology - tb >> .
The Mechanical Universe - caltech >> .

Wartime Radio The Secret Listeners BBC (1979) > .

London's Old Phone Boxes > .

https://www.thegreatcoursesdaily.com/radio-television-history-of-electronic-communication/
https://www.thegreatcoursesdaily.com/who-invented-radio-astronomy-a-history-of-the-radio-telescope/

Engines, Machines, Railways, Vehicles

Britain's Greatest Machines - 1910s > .
Engines - tb >> .
Machines - tb >> .
Railways - tb >> .
Vehicles - tb >> .

Evolution of Military 4x4s

Evolution of Military 4x4s > .

Sunday, September 22, 2019

Glow-worms WW1

WW1 glow-worms

During WWI, when an Allied soldier wanted to read a map or letter at night ... the usual method was to pluck up enough glow-worms to suit your particular lighting needs and put them into a jar or bottle. Though the strength of the glow tended to vary, even just a few of them was usually enough for a given soldier to read a letter or map without being too bright to risk attracting enemy fire. If you wanted brighter, you could pluck up several dozen choice specimens and have yourself a natural lantern.

As you may or may not know, the word “glow-worm” or “glowworm”, depending on where in the world you are, encompasses a vast array of different creatures. In this case, we’re specifically discussing Lampyris noctiluca, which is also known as the European glow-worm or the firefly, in this piece. But the term, “glow-worm” itself can refer to a number of species including mycetophilidae (fungus gnats), phengodidae (glowworm beetles) and rhagophthalmidae (which are also sometimes known as fireflies).

One thing all of these creatures have in common is that the way they produce light is amazingly efficient. For instance, the way fireflies and similar creatures produce light (See: How a Firefly Glows) is almost 100% efficient, meaning that exceptionally little energy is wasted doing anything but creating light, rather than, say, heat. For comparison’s sake, a standard incandescent light-bulb typically only converts about 5%-10% of the energy pumped into it into light, with the remaining being turned into heat. While LED light bulbs are becoming more and more energy efficient every year (presently as high as 80% more efficient than incandescents), they still haven’t managed to match that of the lowly glow-worm, lumen for lumen.

Glowing in the Trenches

todayifoundout.com

GPS

How The Cold War Gave Us Google Maps > .
Then This Happened - Bloom >> .

GPS - Global Positioning Systems ..

Saturday, September 21, 2019

Hot-bulb Engines

Hot Bulb Engines

Slow Runner Model Hot-bulb Semi-diesel Engine
https://www.youtube.com/watch?v=SVOgWrhM67A

World smallest working two-stroke cross-head hot-bulb engine
https://www.youtube.com/watch?v=UGksYSwFucI

Friday, September 20, 2019

Innovations - Army (1954-66)

1954
https://www.youtube.com/watch?v=ohMalo72jXQ

Army Innovations (1965) > .
https://www.youtube.com/watch?v=dVOL1GCtrMU .

1966
https://www.youtube.com/watch?v=SntsT0CqllU

Israel's High-Tech Rise

How Israel became a high-tech military superpower - CaRe > .

24-4-5 Israel's Lavender System, AI Targeting, Battlefield Informatics - McBeth > .

24-2-8 Israel: High-Tech Military; Intelligence Failure - Caspian > .

24-2-1 Why [despite weakist antisemitism] US Supports and Funds Israel | WSJ > .

23-11-7 Scientific Progress & War - [Counterproductive for Ruscia] (subs) - Katz > .

23-9-5 Israel's Everlasting [Internal & External] War - gtbt > .

23-7-26 Ukraine tech sector goes to war | FT Doc > .

Why Israel is a Tech Capital - Poly > .

Why the Israel Army is So Effective - VisPol > .

1948 Creation of Israel - Cold War > .

First Arab - Israeli War 1948 - Cold War Doc - K&G > .

Six-Day War (1967) - Third Arab–Israeli War Doc - K&G > .

Yom Kippur War 1973 - Sinai Front Doc - K&G > .

How Israel's Iron Dome Actually Works - BlQu > .

Israel's ~~Golden Dome~~ Iron Dome - TLDR > .

Israel's Military Technology | Iron Dome | Gaza Conflict - Moco > .

Is Israel's Iron Dome Defense System the Best in the World? - Maha > .

Israel’s Iron Dome Defence System Helps Counter Palestine’s Rocket Attacks - crux > .

Israel's Iron Dome Defense System - Mah > .

Kamikaze Drone - Loitering Munition ..

2021 Will Saudi Arabia Recognise Israel? - KJ R > .

2021 Israel's economic, diplomatic, military success; problematic Palestinians - VP > .

21-5-19 Israel-Hamas Conflict: 3 Reasons Old Dynamics Prevail | WSJ > .

21-5-27 How Israel defends itself against Palestinian rocket attacks? - VisPol > .

2020 BuyBull prophecy, Evangelicals, Idiot-in-Cheat's Middle East fakery > .

Geopolitics of Israel - CaRe > . skip ad > .

Complex History Of The Israeli–Palestinian Conflict - AH Nerd > .

GMD - Ground-Based Midcourse Defense > Air Defense >>

24-4-19 GMD - America's Missile Defense - T&P > .

24-4-19 Over The Horizon Super Radars: Australia (JORN), US, Xina, Ruscia - S&AC > .

1848 Middle East 2020 ..
47-11-29 UN partition plan - Palestine ..

Arab-Israeli Normalization? ..

Dead Sea Sinkholes ↬

Israel - Geopolitics ..
Israel & Palestine ..

Israel's High-Tech Rise ..

Jordan-Israel-Palestine ..

NON-solution ⇻
Powers' Perspectives on Israel-Palestine Clash ..
Turkey-Israel Maritime Plot ..

Inventors

Jones ..
Technological Innovation - Timeline ..

Reginald Victor Jones .

Thursday, September 19, 2019

Ju-88s + radar captured

Luftwaffe Defection 43-5-9 > .
Ju-88 nightfighter with FuG-202 Lichtenstein radar.

Big Ego versus Dowding; nightfighters > .

https://en.wikipedia.org/wiki/Junkers_Ju_88 .
https://en.wikipedia.org/wiki/Lichtenstein_radar .
https://en.wikipedia.org/wiki/Night_fighter .

Wednesday, September 18, 2019

Kammhuber Line

Kammbuber Line & German Radar > .
Operation Biting - Raid on Bruneval - tnh > .

How Germany Lost the Radar Race in WW2 - Binkov > . skip ad > .

Himmelbett Radar System - Luftwaffe | War Stories > .

The Kammhuber Line was the Allied name given to the German night air defense system established in July 1940 by Colonel Josef Kammhuber. It consisted of a series of control sectors equipped with radars and searchlights and an associated night fighter. Each sector would direct the night fighter into visual range with target bombers.

The Line was very effective against early Bomber Command tactics. However, the German method was analyzed by the RAF and a counter measure developed. On the night of 30/31 May 1942 in its 1,000 plane raid against Cologne Bomber Command introduced the use of the bomber stream. The concentration of bombers through a few of the boxes resulted in the defenses being overwhelmed. In response, the Germans converted their ground radar into a radar network, which would follow the path of the British bombers, while a controller directed the night fighters into the stream. Measure and counter measure continued until October 1944, when German defenses were no longer able to respond..........

When Germany organised its air defences into the Kammhuber Line, it was realised by the British (Bomber Command's Operational Research Section (BC-ORS)) that if the RAF bombers were to fly in a bomber stream they could overwhelm the night fighters who flew in individual cells directed to their targets by ground controllers. It was then a matter of calculating the statistical loss from collisions against the statistical loss from night fighters to calculate how close the bombers should fly to minimise RAF losses.

British intelligence soon discovered the nature of the Kammhuber Line and started studying ways to defeat it. At the time RAF Bomber Command sent in their planes one at a time to force the defenses to be spread as far apart as possible, meaning that any one aircraft had to deal with little concentrated flak. This also meant the Himmelbett centres were only dealing with perhaps one or two planes at a time, making their job much easier.

At the urging of R.V. Jones, Bomber Command reorganized their attacks into streams of bombers – the so-called Bomber stream, carefully positioned so the stream flew down the middle of a single cell. Data provided to the British scientists allowed them to calculate that the bomber stream would overwhelm the six potential interceptions per hour that the German "Tame Boar" (Zahme Sau) night fighters could manage in a Himmelbett zone. It was then a matter of calculating the statistical loss from collisions against the statistical loss from night fighters to calculate how close the bombers should fly to minimise RAF losses. The introduction of Gee radio navigation in 1942 allowed the RAF bombers to fly by a common route and at the same speed to and from the target, each aircraft being allotted a height band and a time slot in a bomber stream to minimize the risk of collision. The first use of the bomber stream was the first 1,000 bomber raid against Cologne on the night of 30/31 May 1942. This tactic was extremely effective, leading to fighting between Kammhuber and Erhard Milch, his boss.

Although the success rate of the Line dropped, the network of radars and plotting stations continued to prove their worth. Now when a raid started, night fighters from any base within range were directed into the stream, where it was hoped they would be able to find aircraft with their radar. At the same time a massive building program started to add hundreds of Würzburgs to the system, although the infrastructure needed was extensive. The boxes were initially the radius of the Würzburg radars, about 22 miles, but more powerful radar later on made the boxes up to 100 miles across. Eventually, the line of boxes was several deep, especially around larger towns and the Ruhr valley. Once again the system started to score increasing successes against the British raids.

The British were ready for this development, and as soon as the rates started to improve – for the Germans – they introduced "Window". Dropping strips of foil from a number of "lead" bombers, the German radar operators saw what appeared to be a stream entering their box, each packet of chaff appearing to be a bomber on their displays. Night fighters were then sent to attack this stream, only to find empty space. Just as the fighters reached the false stream, the "real" stream appeared hundreds of miles away, too far to be attacked. The first time this was used was during Operation Gomorrah (a week-long bombing campaign against Hamburg) and proved spectacularly effective. The German radar operators eventually learned to spot the lead bombers at the edge of the windowing, making it less effective. The British had held back from introducing Window for over a year lest the technique be adopted by the Germans and used against British cities.

A more sophisticated method for blinding the German radar was "Mandrel", a jamming signal broadcast from aircraft accompanying the bomber stream or later certain bombers themselves. This progressed into jamming techniques against individual German radar types and spoofing radars to see bomber streams that weren't there. The British also attacked the communications between ground stations and fighters, with Operation Corona, broadcasting false directions in authentic accents over the radio.

One other element was long-range nightfighters operating against the German nightfighters, using a system called "Serrate" to home in on the German nightfighter radar signals. At least three squadrons equipped with Bristol Beaufighter and de Havilland Mosquito were part of No. 100 Group RAF supporting Bomber Command with electronic countermeasures.

https://en.wikipedia.org/wiki/Operations_research
.......
The Line was very effective at first, but was soon rendered useless by a simple change in tactics. The RAF directed all of its bombers to fly in a single stream, overwhelming the sectors, who could only intercept a single aircraft at a time. This led to a dramatic drop in interception rates compared to the raid size. The Line was eventually turned into a radar network, and the night fighters improved with their own radar sets to allow them to hunt on their own.
https://en.wikipedia.org/wiki/Kammhuber_Line .

Kettenkrad

Kettenkrad > .

Was the Kettenkrad useless? > .

The Sd.Kfz. 2 (Sonderkraftfahrzeug 2), better known as the Kleines Kettenkraftrad HK 101 or Kettenkrad for short (pl. Kettenkräder; where Ketten means "chains" or "tracks" and krad is the military abbreviation of the German word Kraftrad, the administrative German term for motorcycle), started its life as a light tractor for airborne troops. The vehicle was designed to be delivered by Junkers Ju 52 aircraft, though not by parachute. The vehicle had the advantage of being the only gun tractor small enough to fit inside the hold of the Ju 52, and was the lightest mass-produced German military vehicle to use the complex Schachtellaufwerk overlapped and interleaved road wheels used on almost all German military half-track vehicles of WW2.

Steering the Kettenkrad was accomplished by turning the handlebars: Up to a certain point, only the front wheel would steer the vehicle. A motion of the handlebars beyond that point would engage the track brakes to help make turns sharper. It was also possible to run the vehicle without the front wheel installed and this was recommended in extreme off-road conditions where speed would be kept low.

The Sd.Kfz. 2 was designed and built by the NSU Werke AG at Neckarsulm, Germany. Patented in June 1939, it was first used in the invasion of the Soviet Union in 1941. Later in the war Stoewer from Stettin also produced Kettenkrads under license, accounting for about 10% of the total production.

Most Kettenkräder saw service on the Eastern Front, where they were used to lay communication cables, pull heavy loads and carry soldiers through the deep Russian mud. Later in the war, Kettenkräder were used as runway tugs for aircraft, especially for the Messerschmitt Me 262 jet fighter, and sometimes the Arado Ar 234 jet reconnaissance-bomber. In order to save aviation fuel, a German jet aircraft would be towed to the runway, rather than taxiing under its own power.

The vehicle was also used in the North African theater and on the Western Front.

The Kettenkrad came with a special trailer (Sd.Anh.1) that could be attached to it to improve its cargo capacity.

Being a tracked vehicle, the Kettenkrad could climb up to 24° in sand and even more on hard ground.

Only two significant sub-variations of the Kettenkrad were constructed. Production of the vehicle was stopped in 1944, at which time 8,345 had been built. After the war, production resumed at NSU. Around 550 Kettenkräder were built for agricultural use, with production ending in 1948 (some sources say 1949).

https://en.wikipedia.org/wiki/Sd.Kfz._2

Tuesday, September 17, 2019

Lorenz Beam

Battle of the Beams ..

The Lorenz beam was a blind-landing radio navigation system developed by C. Lorenz AG in Berlin. The first system had been installed in 1932 at Berlin-Tempelhof Central Airport, followed by Dübendorf in Switzerland (1934) and others all over the world. The Lorenz company referred to it simply as the Ultrakurzwellen-Landefunkfeuer, "ultra-short-wave landing radio beacon", or LFF. In the UK it was known as Standard Beam Approach (SBA).

Prior to the start of WW2, the Germans deployed the system at many Luftwaffe airfields in and outside Germany and equipped most of their bombers with the radio equipment needed to use it. It was also adapted into versions with much narrower and longer-range beams that was used to guide the bombers on missions over Britain, under the name Knickebein and X-Gerät.

Beam navigation works for a single point in space, making it useful for landing or bombing, but not as a general purpose navigation system. This led to a rotating version of the same system for air navigation known as Elektra. Further development produced a system that worked over very long distances, hundreds or thousands of kilometres, known as Sonne (or often, Elektra-Sonnen) that allowed aircraft and U-Boats to take fixes far into the Atlantic. The British captured Sonne receivers and maps and started to use it for their own navigation under the name Consol.
...
The Lorenz system worked by feeding a special three-element antenna system with a modulated radio signal. The signal was fed to the centre dipole, which had a slightly longer reflector element on either side set slightly back. A switch rapidly alternated the opened midpoint connection of each reflector in turn, sending the beam slightly to the left and then slightly to the right of the centreline of the runway. The beams widened as they spread from the antennas, so there was an area directly off the runway approach where the two signals overlapped. The switch was timed so it spent longer on the right side of the antenna than the left.

Lorenz used a single radio transmitter at 33.33 MHz (Anflugfunkfeuer) and three antennas placed in a line parallel to the end of the runway. The center antenna was always powered, while the other two were short-circuited by a mechanical rotary switch turned by a simple motor. This resulted in a "kidney" shaped broadcast pattern centered on one of the two "side" antennas depending on which antenna had been short-circuited. The contacts on the switch were set so that one antenna was shorted for the time to be considered a "Dot" by a morse operator and the other as a "Dash". The signal could be detected for some distance off the end of the runway, as much as 30 km. The Lorenz obtained a sharper beam than could be created by an aerial array by having two lobes of signal.

An aircraft approaching the airport would tune one of their radios to the Lorenz frequency. If the crew was on the left side of the centreline, they would hear a series of short tones followed by long pauses, meaning the aircraft was on the "dot" side of the antenna. Hearing the "dots", they would know that they had to turn to the right in order to fly down the centreline. If the crew was on the right side of the centerline, they would hear a series of long tones followed by short pauses, meaning the aircraft was on the "dash" side of the antenna. Hearing the "dashes", they would know that they had to turn to the left in order to fly down the centreline. In the centre, the radio would receive both signals, where the dots filled in the gaps in the dashes and produced a continual signal, the so-called "equisignal". Flying in the known direction of the runway and keeping the equisignal on the radio, the Lorenz could guide an aircraft down a straight line with a relatively high degree of accuracy, so much so that the aircraft could then find the runway visually except in the worst conditions.

https://en.wikipedia.org/wiki/Lorenz_beam .
https://en.wikipedia.org/wiki/Battle_of_the_Beams .

Monday, September 16, 2019

MIT

MIT Ideas Factory ↠

MIT women, 20s, 30s
http://alumweb.mit.edu/groups/amita.old/esr/prewar.html

Technology women
http://alumweb.mit.edu/groups/amita.old/esr/practitioners.html

MIT history
https://libraries.mit.edu/mithistory/community/notable-persons/ellen-swallow-richards/ .

Saturday, September 14, 2019

Oz inventions & engineering

https://www.youtube.com/watch?v=YrxF9ihMjhw .

Friday, September 13, 2019

Polyethylene, radar, and submarine cables

Transatlantic Telegraph Cable: A Tale of Extraordinary Perseverance - Mega > .

24-2-16 Undersea Cables, Saboutage, Internet, Surveillance - CuDr > . skip > .

24-2-7 Could Houthi Sever Global Underwater Cables off Yemen's Coast? - Sal > .

23-12-20 Undersea fibre-optic cables could be geopolitical frontier | ABC Aus > .

23-12-5 Protecting Allied critical undersea infrastructure - NATO > .

23-9-30 Internet Backbone = Hidden Infrastructure - B1M > .

23-6-30 US & Xina Squabbling over SEA-ME-WE 6 Cable - Half > .

22-10-14 [Cables another target for P00tin's desperate sabotage?] - nwyt > .

22-9-21 How Xina’s Military Drills Could Choke Off Taiwan’s Internet | WSJ > .
Undersea Communication Cables - Mega > .

Why 17 Million Telegrams Are Still Sent Every Year - Half > .
Communication, Surveillance - PrTe >> .

Infrastructure Vulnerabilities - Compass Rose >> .

Polyethylene, radar, and submarine cables

Communication infrastructure ..

"They had heated a mixture of ethylene and benzaldehyde to 170°C (338°F), using apparatus that could submit materials to a pressure of 1,900 atmospheres (1,925 bars). But the reactions were explosive and safety concerns prompted the now defunct ICI, which merged into Dutch-based Akzo Nobel, to halt the research.

In December that year, Williams and colleagues Michael Perrin and John Paton reinvestigated the experiments of Gibson and Fawcett using ethylene alone. Under similar experimental conditions - but with better equipment - they observed a pressure drop, and when the reaction finished there were 8.5g of white PE powder.

Williams, Perrin and Paton had been lucky. The vessel had leaked and, it was later confirmed, a trace of oxygen was present in the fresh ethylene that had been added to the reaction vessel to replace the leaked gas. The fresh ethylene contained, by chance, the right amount of oxygen to act as an initiator.

"For once it didn't explode - usually it did - and we thought something must be wrong. So we left it to cool overnight. And when I looked inside the metal container the next day, I found what looked like a lump of sugar. In fact, that 'sugar' was polythene."

Uses for early PE were limited, as the material was soft and had a low melting point. This was because under the high pressure polymerization process the ethylene molecules did not always add in a regular chain.

A member of ICI's dyestuffs division, Bernard Habgood, recognized that PE could supersede gutta-percha, a natural material, for insulation of submarine cables. This provided the impetus to proceed to commercial scale production. The first full-scale PE plant, with a 100 tonne/year capacity, went into production on September 1, 1939, the day Germany invaded Poland and war became unavoidable for Britain.

ICI's work on PE changed during the Second World War, when the material was used to insulate airborne radar equipment. During the development of radar in the early war years it had proved difficult to insulate the equipment to prevent power loss and thus preserve the strength of the signal. PE's electrical insulation properties enabled the British forces to reduce the weight of radar equipment and allowed them to place radars inside fighter planes. This provided an enormous technical advantage in long-distance warfare, most significantly in the Battle of the Atlantic against German submarines. The Germans were obliged to use a bulkier insulating material for their radar, which was less effective."
http://www.icis.com/resources/news/2008/05/12/9122447/polyethylene-discovered-by-accident-75-years-ago/

https://en.wikipedia.org/wiki/Polyethylene
http://www.polymer-search.com/inventionplastic.html
http://www.acs.org/content/acs/en/education/whatischemistry/landmarks/polypropylene.html

http://www.independent.co.uk/news/science/polythenes-story-the-accidental-birth-of-plastic-bags-800602.html .

Pages

Monday, September 30, 2019

●● Technology

Saturday, September 28, 2019

ASV AI RDF

Friday, September 27, 2019

Battle of Britain & RDF

Thursday, September 26, 2019

Communication Infrastructure