Picture of the day
- Thread starter jwhc
- Start date
Dark Alley Dan
CGN Ultra frequent flyer
- Location
- Darkest Edmonton
Lead Azide sounds a treat to work with. Sensitive enough to be set off by the heat generated by an impure thought.
A lotta OHSA guys would get hives just looking at those pics. Considering the nature of magazine fires and explosions and the quantities on hand, one wonders if all those slides weren't a bit of theatre rather than a solid go-to safety plan.
Still, the processes must have been sound. Picatinny Arsenal still stands.
A lotta OHSA guys would get hives just looking at those pics. Considering the nature of magazine fires and explosions and the quantities on hand, one wonders if all those slides weren't a bit of theatre rather than a solid go-to safety plan.
Still, the processes must have been sound. Picatinny Arsenal still stands.
Don't forget static discharge:
"Energies involved
The energy released in a static electricity discharge may vary over a wide range. The energy in joules can be calculated from the capacitance (C) of the object and the static potential V in volts (V) by the formula E = ½CV2.[22] One experimenter estimates the capacitance of the human body as high as 400 picofarads, and a charge of 50,000 volts, discharged e.g. during touching a charged car, creating a spark with energy of 500 millijoules.[23] Another estimate is 100–300 pF and 20,000 volts, producing a maximum energy of 60 mJ.[24] IEC 479-2:1987 states that a discharge with energy greater than 5000 mJ is a direct serious risk to human health. IEC 60065 states that consumer products cannot discharge more than 350 mJ into a person.
The maximal potential is limited to about 35–40 kV, due to corona discharge dissipating the charge at higher potentials. Potentials below 3000 volts are not typically detectable by humans. Maximal potential commonly achieved on human body range between 1 and 10 kV, though in optimal conditions as high as 20–25 kV can be reached. Low relative humidity increases the charge buildup; walking 20 feet (6 m) on vinyl floor at 15% relative humidity causes buildup of voltage up to 12 kV, while at 80% humidity the voltage is only 1.5 kV.[25]
As little as 0.2 millijoules may present an ignition hazard; such low spark energy is often below the threshold of human visual and auditory perception.
Typical ignition energies are:
0.017 mJ for hydrogen,
0.2–2 mJ for hydrocarbon vapors,
1–50 mJ for fine flammable dust,
40–1000 mJ for coarse flammable dust.
The energy needed to damage most electronic devices[specify] is between 2 and 1000 nanojoules.[26]"
"Energies involved
The energy released in a static electricity discharge may vary over a wide range. The energy in joules can be calculated from the capacitance (C) of the object and the static potential V in volts (V) by the formula E = ½CV2.[22] One experimenter estimates the capacitance of the human body as high as 400 picofarads, and a charge of 50,000 volts, discharged e.g. during touching a charged car, creating a spark with energy of 500 millijoules.[23] Another estimate is 100–300 pF and 20,000 volts, producing a maximum energy of 60 mJ.[24] IEC 479-2:1987 states that a discharge with energy greater than 5000 mJ is a direct serious risk to human health. IEC 60065 states that consumer products cannot discharge more than 350 mJ into a person.
The maximal potential is limited to about 35–40 kV, due to corona discharge dissipating the charge at higher potentials. Potentials below 3000 volts are not typically detectable by humans. Maximal potential commonly achieved on human body range between 1 and 10 kV, though in optimal conditions as high as 20–25 kV can be reached. Low relative humidity increases the charge buildup; walking 20 feet (6 m) on vinyl floor at 15% relative humidity causes buildup of voltage up to 12 kV, while at 80% humidity the voltage is only 1.5 kV.[25]
As little as 0.2 millijoules may present an ignition hazard; such low spark energy is often below the threshold of human visual and auditory perception.
Typical ignition energies are:
0.017 mJ for hydrogen,
0.2–2 mJ for hydrocarbon vapors,
1–50 mJ for fine flammable dust,
40–1000 mJ for coarse flammable dust.
The energy needed to damage most electronic devices[specify] is between 2 and 1000 nanojoules.[26]"
Dark Alley Dan
CGN Ultra frequent flyer
- Location
- Darkest Edmonton
The A-10 N/AW - for when you want a friend along.
It never actually fought the war it was designed for, which was to take out Soviet tanks coming through the Fulda Gap.
Grizz
Posted by Jonathan Gray
A story that was naturally hushed up during wartime. The collision between the KGV Battleship and her escorting destroyer Punjabi.
On the 28th April - KGV (Flag CinC Home Fleet) USS WASHINGTON, Carrier VICTORIOUS, heavy cruisers USS WICHITA and TUSCALOOSA, and light cruiser KENYA escorted by destroyers sailed from Scapa and set course northerly to provide distant cover for convoys PQ 15 (on its way to Murmansk in Russia with vital materials)
and QP 11.
On the 30th Punjabi and a number of other destroyers arrived to re-leave those already in attendance.
On 1st May - At 1545 hours north east of Iceland in thick fog the Battlefleet was zigzagging when they ran into a thick bank of fog immediately KGV made a signal to cease zigzagging. Destroyer PUNJABI failed to receive the signal and carried on zigzagging and crossed under the flagship's bows. KGV travelling at 25 knots cut PUNJABI clean in half, PUNJABI's stern sank almost immediately. The collision caused a 40 foot gash in the bow of KING GEORGE V and also under water damage. As the stern of PUNJABI sank her ready use depth charges exploded directly under the keel of the WASHINGTON the vessel immediately astern of KGV,, causing slight damage to WASHINGTON.
The fore section of PUNJABI sank slowly which enabled many of her crew to abandon ship. Destroyers MARNE and MARTIN were able to pick up 201 survivors. 49 were lost mainly from the stern section. RIP.
Kenneth Tipper a telegraphist aboard Punjabi, picks up the story......
We had left Iceland five days before and were in Arctic waters when at 15:45 on May 1st a thick fog descended on the fleet. I was in the main wireless cabin in the forward part of the ship, prior to relieving another telegraphist in the cabin aft where we conducted our interception work.
Suddenly there was a tremendous crash, the Punjabi heeled over sharply on its side, and all the lights went out. First thought was that we had been torpedoed, but our nemesis turned out to be one of our own ships - the battleship King George V had rammed and cut in half our 1,850-ton destroyer.
I made my way up on deck, and soon after we got the order to abandon ship. Sliding down the sloping side of the forward part of the ship, I got a liberal coating of fuel oil on entering the freezing water. No swimmer, I looked around after coming to the surface, and was lucky to grab onto a Carley Float nearby, hoisting myself onto the side where I sat in freezing water until we were picked up by the destroyer HMS. Martin.
As our stricken ship lay in two halves in the water, she was narrowly missed both by the USS. Washington and HMS. Victorious. The Punjabi's depth charges blew up as the stern sank, and the crew of the Washington felt the concussion as they passed by.
The incident was kept secret until the end of the war, and a court of enquiry decided that Punjabi, in the fog, had turned across the bows of the battleship after being told to alter course to avoid a floating mine.
Miraculously, only 49 of the Punjabi's crew were lost in what was one of the most bizarre incidents in World War 2. There were 201 survivors, who, in another twist of fate, were transferred to the battleship that sank their ship, in Iceland for the return trip to Scapa Flow, the Home Fleet anchorage in the Orkney and Shetland Islands. The King George V, with a huge gash in her bows, needed to return to Liverpool for repairs.
Ken died in April 2018 aged 96 RIP.
On arrival at Liverpool KGV entered Gladstone dock and was taken in hand for repairs, refit, and upgrade ( radar Type 285 installed for fire-control of 5.25in mountings and the newly developed surface warning radar Type 273Q was also fitted)
The damage sustained by KING GEORGE V in the collision extended from the Bow to number 16 station below the main deck, both sides of the ship were open to the sea. The starboard outer wing compartments 119 to 140 were flooded as a result of the depth charge explosions.
The work took place from May - July 1942, she rejoined the fleet at Scapa 11 July. After working up and trials of the new radar equipment, on the 24th the flag of CinC Home Fleet, was transferred from DoY to KGV.
Photos have captions.
KGV AT REST IN SEIDESFJORD, ICELAND.
PHOTOGRAPHED FROM THE DESTROYER HMS WHEATLAND.
HMS KING GEORGE V AFTER COLLISION WITH HMS PUNJABI. 17 MAY 1942, GLADSTONE DOCK, LIVERPOOL.
© IWM A 9949
HMS KING GEORGE V AFTER COLLISION WITH HMS PUNJABI. 17 MAY 1942, GLADSTONE DOCK, LIVERPOOL.
© IWM A 9950
(not posted very often)
DAMAGE TO STARBOARD SIDE OF HULL (MIDSHIPS).
© IWM A 9952
PUNJABI AT ANCHOR.
A story that was naturally hushed up during wartime. The collision between the KGV Battleship and her escorting destroyer Punjabi.
On the 28th April - KGV (Flag CinC Home Fleet) USS WASHINGTON, Carrier VICTORIOUS, heavy cruisers USS WICHITA and TUSCALOOSA, and light cruiser KENYA escorted by destroyers sailed from Scapa and set course northerly to provide distant cover for convoys PQ 15 (on its way to Murmansk in Russia with vital materials)
and QP 11.
On the 30th Punjabi and a number of other destroyers arrived to re-leave those already in attendance.
On 1st May - At 1545 hours north east of Iceland in thick fog the Battlefleet was zigzagging when they ran into a thick bank of fog immediately KGV made a signal to cease zigzagging. Destroyer PUNJABI failed to receive the signal and carried on zigzagging and crossed under the flagship's bows. KGV travelling at 25 knots cut PUNJABI clean in half, PUNJABI's stern sank almost immediately. The collision caused a 40 foot gash in the bow of KING GEORGE V and also under water damage. As the stern of PUNJABI sank her ready use depth charges exploded directly under the keel of the WASHINGTON the vessel immediately astern of KGV,, causing slight damage to WASHINGTON.
The fore section of PUNJABI sank slowly which enabled many of her crew to abandon ship. Destroyers MARNE and MARTIN were able to pick up 201 survivors. 49 were lost mainly from the stern section. RIP.
Kenneth Tipper a telegraphist aboard Punjabi, picks up the story......
We had left Iceland five days before and were in Arctic waters when at 15:45 on May 1st a thick fog descended on the fleet. I was in the main wireless cabin in the forward part of the ship, prior to relieving another telegraphist in the cabin aft where we conducted our interception work.
Suddenly there was a tremendous crash, the Punjabi heeled over sharply on its side, and all the lights went out. First thought was that we had been torpedoed, but our nemesis turned out to be one of our own ships - the battleship King George V had rammed and cut in half our 1,850-ton destroyer.
I made my way up on deck, and soon after we got the order to abandon ship. Sliding down the sloping side of the forward part of the ship, I got a liberal coating of fuel oil on entering the freezing water. No swimmer, I looked around after coming to the surface, and was lucky to grab onto a Carley Float nearby, hoisting myself onto the side where I sat in freezing water until we were picked up by the destroyer HMS. Martin.
As our stricken ship lay in two halves in the water, she was narrowly missed both by the USS. Washington and HMS. Victorious. The Punjabi's depth charges blew up as the stern sank, and the crew of the Washington felt the concussion as they passed by.
The incident was kept secret until the end of the war, and a court of enquiry decided that Punjabi, in the fog, had turned across the bows of the battleship after being told to alter course to avoid a floating mine.
Miraculously, only 49 of the Punjabi's crew were lost in what was one of the most bizarre incidents in World War 2. There were 201 survivors, who, in another twist of fate, were transferred to the battleship that sank their ship, in Iceland for the return trip to Scapa Flow, the Home Fleet anchorage in the Orkney and Shetland Islands. The King George V, with a huge gash in her bows, needed to return to Liverpool for repairs.
Ken died in April 2018 aged 96 RIP.
On arrival at Liverpool KGV entered Gladstone dock and was taken in hand for repairs, refit, and upgrade ( radar Type 285 installed for fire-control of 5.25in mountings and the newly developed surface warning radar Type 273Q was also fitted)
The damage sustained by KING GEORGE V in the collision extended from the Bow to number 16 station below the main deck, both sides of the ship were open to the sea. The starboard outer wing compartments 119 to 140 were flooded as a result of the depth charge explosions.
The work took place from May - July 1942, she rejoined the fleet at Scapa 11 July. After working up and trials of the new radar equipment, on the 24th the flag of CinC Home Fleet, was transferred from DoY to KGV.
Photos have captions.
KGV AT REST IN SEIDESFJORD, ICELAND.
PHOTOGRAPHED FROM THE DESTROYER HMS WHEATLAND.
HMS KING GEORGE V AFTER COLLISION WITH HMS PUNJABI. 17 MAY 1942, GLADSTONE DOCK, LIVERPOOL.
© IWM A 9949
HMS KING GEORGE V AFTER COLLISION WITH HMS PUNJABI. 17 MAY 1942, GLADSTONE DOCK, LIVERPOOL.
© IWM A 9950
(not posted very often)
DAMAGE TO STARBOARD SIDE OF HULL (MIDSHIPS).
© IWM A 9952
PUNJABI AT ANCHOR.
Really? I was stationed in NW Germany for four years during the Cold War.
Our air cover was RCAF Starfighters armed with nukes, an aircraft designed as a high altitude interceptor that the Luftwaffe could not keep in the air. We had the "Honest John" short range nuke missile. Reassuring - NOT! The Brits had some ground support aircraft in the forum of the Hawker Hunter but the rocket carrying helicopters of Viet Nam War fame were not in plentiful if they existed at all.
I think the A10 Warthog would have been a blessing had it been available to plug the Fulda Gap.
Our air cover was RCAF Starfighters armed with nukes, an aircraft designed as a high altitude interceptor that the Luftwaffe could not keep in the air. We had the "Honest John" short range nuke missile. Reassuring - NOT! The Brits had some ground support aircraft in the forum of the Hawker Hunter but the rocket carrying helicopters of Viet Nam War fame were not in plentiful if they existed at all.
I think the A10 Warthog would have been a blessing had it been available to plug the Fulda Gap.
The context of the earlier comment was the A-10 in Operation Desert Storm, during which roughly five A-10s were downed (a roughly 3.5% loss rate) in exchange for the destruction of over 4,000 enemy Iraqi vehicles and many other targets.
So, while obviously the A-10 would have been a welcome sight for NATO troops over the Fulda Gap, if a war in central Europe had occurred, the losses there would have been many times worse than in the desert in 1991.
Obligatory photo follows.
Just one of a hundreds of stories of survival at sea.
Poon Lim
Lim worked as second steward on SS Benlomond, a British merchant ship, when it was sunk by U-172, a German U-boat, on 23 November 1942.Picked up on 5 April 1943, after spending 133 days in Carley Float.
Passed away in 1991.
Carley Floats are one of those things in the background that's always in a way but can save one's life when needed (unless you are in freezing water).
I remember hating those passionately when making ships models.
Poon Lim
Lim worked as second steward on SS Benlomond, a British merchant ship, when it was sunk by U-172, a German U-boat, on 23 November 1942.Picked up on 5 April 1943, after spending 133 days in Carley Float.
Passed away in 1991.
Carley Floats are one of those things in the background that's always in a way but can save one's life when needed (unless you are in freezing water).
I remember hating those passionately when making ships models.
Last edited:
Donny Fenn1
CGN Ultra frequent flyer
- Location
- East Kootenays
Attachments
In the reading I've done on the Battle of Britain, pilot fatigue was definitely a major factor. Same for the Battle of Malta. The pilots of the Desert Air Force were similarly sleep deprived.
Between sorties, some opted to sleep under the wings of their aircraft or even the cockpit. It was less stressful than staggering off to quarters only to return on the next alarm.
Between sorties, some opted to sleep under the wings of their aircraft or even the cockpit. It was less stressful than staggering off to quarters only to return on the next alarm.
Dark Alley Dan
CGN Ultra frequent flyer
- Location
- Darkest Edmonton
A fast bird in atypical plumage.
March 19th 1945.
Essex-class carrier USS Franklin (CV-13) after 5"/38 twin turret burning. She had been hit by a Japanese air attack while operating off the coast of Japan.
Photographed from USS Santa Fe (CL-60), which extinguished the fire in this gun mount by playing streams of water through the mount's open door.
The other 5"/38 twin gun mount and the *40 mm *quad gun at right also burned.
Essex-class carrier USS Franklin (CV-13) after 5"/38 twin turret burning. She had been hit by a Japanese air attack while operating off the coast of Japan.
Photographed from USS Santa Fe (CL-60), which extinguished the fire in this gun mount by playing streams of water through the mount's open door.
The other 5"/38 twin gun mount and the *40 mm *quad gun at right also burned.
