Post by parajag on Mar 31, 2017 16:17:49 GMT -8
Below is information regarding other military parachutes, to provide a comparison between the above parachutes we use for demonstration/sport jumping and past or current parachutes used for airborne operations.
These are all non-steerable parachutes. In order to control the parachute on landing, you have to pull a slip with the two risers opposite your direction of drift. For example, if the wind is blowing from your left, grasp the left set of risers with both hands and pull them deep into your chest. You can also slip in the air to avoid other jumpers or obstacles on the ground, with either a two or one riser slip. Every paratrooper who has jumped one of these probably has a story of trying to avoid someone or something by grasping one riser and climbing up the riser, practically to the skirt of the canopy. That’s how they would have used the T-5 in WWII.
T-5 PARACHUTE
The T-5 was the parachute used during WWII. It was developed in 1941. Below are some pictures of a replica T-5 parachute I have, made from a combination of NOS parts and custom fabricated webbing. (For sale, by the way.) The T-5 parachute canopy was made of silk, or later, nylon. According to a 1943 student text, the life of the canopy was four years or 100 jumps. I’m not sure whether that service life was for the silk or nylon parachute. (The T-10, MC1-1C, MC-6 and T-11 parachutes have a 12-year service, and combined service and shelf life of 16.5-years.)
The T-5 harness is really uncomfortable. It has no adjustment for the chest strap, nor does it have sizing channels for the diagonal backstraps. The V-rings are not adjustable, “quick fit” V-rings like on the T-10 harness. Instead, the slack in the harness has to be taken up through the metal adjusters. A big shortcoming in the T-5 harness was there was no way to quickly detach the canopy. It has no canopy release assemblies, nor does it have leg strap or chest strap ejector snaps, like the T-10 harness. As you probably know, this was why the WWII paratroopers carried switchblade knives, to cut themselves out of the harness. Jack McNiece said that on D-Day, he simply cut his risers and kept fighting in the harness until he had time to remove it. The lack of a release method for the canopy meant that some paratroopers were dragged on landing and some killed when they drowned in areas in Normandy flooded by the German defenders.
The T-5 had a 28-foot flat circular canopy, with 28 gores and 28 suspension lines. The parachute suspension lines were made of braided silk with a tensile strength of 450 lbs. (Modern suspension lines are made of Type II nylon cord, with a tensile strength of 400 lbs – the silk lines were actually stronger.) Each suspension line was attached to a connector link and extended to the skirt of the canopy through a channel in the silk, over the apex, and down the other side to a diametrically opposite connector link. That made them extremely difficult to replace. An owner of a restored T-5 canopy who had it relined told me the rigger who did it said he would never do it again. The main parachute had a rate of descent of 14-20 fps. The reserve parachute was a 22-foot flat circular canopy and had a rate of descent of 17-26 fps. (But, remember the average enlisted man in WWII weighed something like 145 lbs.)
Jack Wingate jumped with T-5 parachutes in the 1950s. He said that at that time the whole thing was made of silk, and called it “beautiful.” I believe during the war, they were made mostly of nylon since the Japanese quickly overran all the countries that supplied silk.
The entire student text I have on parachute packing is 10 pages long. The actual packing instructions are less than one page. Compare that to the modern TM for the MC-1 parachute which is 373 pages. I imagine what I have might not be the complete rigger manual for the T-5, which must have been longer.
The T-5 parachute suspension lines were stowed in elastic retaining bands inside the pack tray. The parachute did not have a deployment bag. It used a “canopy first” deployment system. The canopy was long folded and then accordion folded on top of the stowed suspension lines. A break cord tie of 3 turns of 16-5 cord, unwaxed, was tied around the break cord attaching loop at the end of the static line and around the suspension lines where they cross at the apex of the canopy. The pack cover assembly was then laced to the pack tray with 2 turns of 16-5 cord, cotton or linen thread. The lacing was designed to break under the weight of a falling body when the static line was extended fully. (The instructions do not give the breaking strength of “16-5 cord” and that is not a modern material I am familiar with. The apex of the T-10, MC1-1C and SF-10A canopies are tied to the buffer loop at the end of the static line with two turns of 80-lb Type I cotton break tape.)
Image showing the inside of a T-5 pack tray.
The deployment sequence of the T-5 was as follows. The jumper fell away from the aircraft, and when he reached the end of the 15-foot static line, the lacing holding the pack cover to the pack tray broke. The pack cover was pulled off the pack tray and the apex of the canopy pulled out. The break cord tie snapped after the canopy was completely out of the pack. The canopy inflated, and then the jumper fell to the end of the suspension lines that came unstowed out of the back of the pack tray. The static line and pack cover stayed with the aircraft. As you probably know, the severe opening shock this deployment method created was why the pockets of the M1942 parachutist uniform were reinforced with tent canvas.
You can see, from the description of how the T-5 parachute worked, why the T-10 deployment system was an improvement. The T-10 (MC1-1C, or SF-10A) parachute is contained in the deployment bag until the line stretch is completed and the two locking stows disengage. The entire parachute then deploys to its full length before the break cord tie at the apex of the canopy separates and the parachute inflates. The opening shock, and strain on the parachutist and equipment, is greatly reduced.
There are some reenactors who jump with T-5 parachutes today. The canopy has to be fitted to a modern approved harness. (Two components in the system must be FAA approved, the harness and the reserve parachute. There is no approval process for main parachutes.) The T-5 canopies are fitted with a 4-line release, like the BA-22. I don’t recommend jumping with an antique parachute. Notice that the T-5 parachutes had a service life of 4 years and 100 jumps. You could buy an “airworthy” T-5 parachute, have it tested, and if it fails the test you just put a hole in your nice minty canopy. The T-5 has no anti-inversion net and back in the day was prone to malfunctions. The descent rate, plus the added forward drive of the 4-line release makes for a high rate of descent. In my opinion, you should only jump a parachute that you can land safely under any conditions. For example, would you want to land that parachute in high winds or on a runway? My interest in living history goes only so far.
The T-5 is not on our ASOP list of approved parachutes, but it is listed here for comparison to the others and for historical interest.
These are all non-steerable parachutes. In order to control the parachute on landing, you have to pull a slip with the two risers opposite your direction of drift. For example, if the wind is blowing from your left, grasp the left set of risers with both hands and pull them deep into your chest. You can also slip in the air to avoid other jumpers or obstacles on the ground, with either a two or one riser slip. Every paratrooper who has jumped one of these probably has a story of trying to avoid someone or something by grasping one riser and climbing up the riser, practically to the skirt of the canopy. That’s how they would have used the T-5 in WWII.
T-5 PARACHUTE
The T-5 was the parachute used during WWII. It was developed in 1941. Below are some pictures of a replica T-5 parachute I have, made from a combination of NOS parts and custom fabricated webbing. (For sale, by the way.) The T-5 parachute canopy was made of silk, or later, nylon. According to a 1943 student text, the life of the canopy was four years or 100 jumps. I’m not sure whether that service life was for the silk or nylon parachute. (The T-10, MC1-1C, MC-6 and T-11 parachutes have a 12-year service, and combined service and shelf life of 16.5-years.)
The T-5 harness is really uncomfortable. It has no adjustment for the chest strap, nor does it have sizing channels for the diagonal backstraps. The V-rings are not adjustable, “quick fit” V-rings like on the T-10 harness. Instead, the slack in the harness has to be taken up through the metal adjusters. A big shortcoming in the T-5 harness was there was no way to quickly detach the canopy. It has no canopy release assemblies, nor does it have leg strap or chest strap ejector snaps, like the T-10 harness. As you probably know, this was why the WWII paratroopers carried switchblade knives, to cut themselves out of the harness. Jack McNiece said that on D-Day, he simply cut his risers and kept fighting in the harness until he had time to remove it. The lack of a release method for the canopy meant that some paratroopers were dragged on landing and some killed when they drowned in areas in Normandy flooded by the German defenders.
The T-5 had a 28-foot flat circular canopy, with 28 gores and 28 suspension lines. The parachute suspension lines were made of braided silk with a tensile strength of 450 lbs. (Modern suspension lines are made of Type II nylon cord, with a tensile strength of 400 lbs – the silk lines were actually stronger.) Each suspension line was attached to a connector link and extended to the skirt of the canopy through a channel in the silk, over the apex, and down the other side to a diametrically opposite connector link. That made them extremely difficult to replace. An owner of a restored T-5 canopy who had it relined told me the rigger who did it said he would never do it again. The main parachute had a rate of descent of 14-20 fps. The reserve parachute was a 22-foot flat circular canopy and had a rate of descent of 17-26 fps. (But, remember the average enlisted man in WWII weighed something like 145 lbs.)
Jack Wingate jumped with T-5 parachutes in the 1950s. He said that at that time the whole thing was made of silk, and called it “beautiful.” I believe during the war, they were made mostly of nylon since the Japanese quickly overran all the countries that supplied silk.
The entire student text I have on parachute packing is 10 pages long. The actual packing instructions are less than one page. Compare that to the modern TM for the MC-1 parachute which is 373 pages. I imagine what I have might not be the complete rigger manual for the T-5, which must have been longer.
The T-5 parachute suspension lines were stowed in elastic retaining bands inside the pack tray. The parachute did not have a deployment bag. It used a “canopy first” deployment system. The canopy was long folded and then accordion folded on top of the stowed suspension lines. A break cord tie of 3 turns of 16-5 cord, unwaxed, was tied around the break cord attaching loop at the end of the static line and around the suspension lines where they cross at the apex of the canopy. The pack cover assembly was then laced to the pack tray with 2 turns of 16-5 cord, cotton or linen thread. The lacing was designed to break under the weight of a falling body when the static line was extended fully. (The instructions do not give the breaking strength of “16-5 cord” and that is not a modern material I am familiar with. The apex of the T-10, MC1-1C and SF-10A canopies are tied to the buffer loop at the end of the static line with two turns of 80-lb Type I cotton break tape.)
Image showing the inside of a T-5 pack tray.
The deployment sequence of the T-5 was as follows. The jumper fell away from the aircraft, and when he reached the end of the 15-foot static line, the lacing holding the pack cover to the pack tray broke. The pack cover was pulled off the pack tray and the apex of the canopy pulled out. The break cord tie snapped after the canopy was completely out of the pack. The canopy inflated, and then the jumper fell to the end of the suspension lines that came unstowed out of the back of the pack tray. The static line and pack cover stayed with the aircraft. As you probably know, the severe opening shock this deployment method created was why the pockets of the M1942 parachutist uniform were reinforced with tent canvas.
You can see, from the description of how the T-5 parachute worked, why the T-10 deployment system was an improvement. The T-10 (MC1-1C, or SF-10A) parachute is contained in the deployment bag until the line stretch is completed and the two locking stows disengage. The entire parachute then deploys to its full length before the break cord tie at the apex of the canopy separates and the parachute inflates. The opening shock, and strain on the parachutist and equipment, is greatly reduced.
There are some reenactors who jump with T-5 parachutes today. The canopy has to be fitted to a modern approved harness. (Two components in the system must be FAA approved, the harness and the reserve parachute. There is no approval process for main parachutes.) The T-5 canopies are fitted with a 4-line release, like the BA-22. I don’t recommend jumping with an antique parachute. Notice that the T-5 parachutes had a service life of 4 years and 100 jumps. You could buy an “airworthy” T-5 parachute, have it tested, and if it fails the test you just put a hole in your nice minty canopy. The T-5 has no anti-inversion net and back in the day was prone to malfunctions. The descent rate, plus the added forward drive of the 4-line release makes for a high rate of descent. In my opinion, you should only jump a parachute that you can land safely under any conditions. For example, would you want to land that parachute in high winds or on a runway? My interest in living history goes only so far.
The T-5 is not on our ASOP list of approved parachutes, but it is listed here for comparison to the others and for historical interest.
