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The boy refused to be paid for climbing the talltree.这句话的refuse为什么是ed形式?他是过去分词吗过去分词和过去式有啥区别?
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过去分词是指完成时或被动语态里面的动词,而过去式就过去时里用的动词.过去分词一般不能单独使用,一般加be的变形 have has had
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refused表过去发生
是过去分词也是过去式这里相同
扫描下载二维码From Wikipedia, the free encyclopedia
Tallboy, or Bomb, Medium Capacity, 12,000 lb, was an
developed by the British aeronautical engineer
and used by the
during the Second World War.
At 5 long tons (5.1 t), it could only be carried by the
heavy bomber. It proved to be effective against massive and hardened structures against which conventional bombing had proved ineffective.
Wallis presented his ideas for a 10-ton bomb in his 1941 paper A Note on a Method of Attacking the Axis Powers, which showed that a very large bomb exploding deep underground next to a target would transmit the shock into the foundations of the target, particularly since shock waves are transmitted through the ground more strongly than through air.
Wallis designed the "" of 50 tons, which would fly at 320 mph (510 km/h) at 45,000 ft (14,000 m) to carry the heavy bomb over 4,000 mi (6,400 km), but the Air Ministry opposed a single-bomb aircraft, and the idea was not pursued after 1942.
The design and production of Tallboy was done without a contract on the initiative of the Ministry, following Wallis' 1942 paper Spherical Bomb—Surface Torpedo and the design of the "" for the
of . As such, the RAF used bombs that they had not bought and which were still the property of
the manufacturer. This situation was normalised once their capabilities were recognised.
Accomplishments of the Tallboy included the 24 June 1944
attack on —along with —which undermined the foundations of
on 8–9 June 1944, when bombs passed straight through the hill and exploded inside the tunnel 60 ft (18 m) below the surface.
The last of the 's , the , was sunk by an air attack using Tallboys.
Most large Allied, particularly British,
aircraft bombs () had very thin skins to maximize the weight of explosive that a bomber could carry. This was an improvement on the early part of the war, when the explosive content of British bomb designs was low.
To be able to penetrate the earth (or ) without breaking apart, the casing of the Tallboy had to be strong. Each was cast in one piece of high-tensile steel that would enable it to survive the impact before detonation. At the same time, to achieve the penetration required, Wallis designed the Tallboy to be very
so that, when dropped from a great height, it would reach a much higher
than traditional bomb designs.
In the final design, the No. 78 Mark I tail of the bomb was about half the overall length of the bomb casing was some 10 ft (3.0 m) of the overall 21-foot (6.4 m) length. Initially, the bomb had a tendency to tumble, so the tail was modified: the fins were given a slight twist so that the bomb spun as it fell. The gyroscopic effect thus generated stopped the pitching and yawing, improved the aerodynamics, and improved accuracy.
Tallboy was designed to be dropped from an optimal altitude of 18,000 ft (5,500 m) at a forward speed of 170 mph (270 km/h), hitting at 750 mph (1,210 km/h). It made a crater 80 ft (24 m) deep and 100 ft (30 m) across and could go through 16 ft (4.9 m) of concrete.
The weight of the Tallboy (approximately 12,000 lb (5.4 t)) and the high altitude required of the bombing aircraft meant that the Avro Lancasters used had to be specially adapted. Armour plating and even defensive armament were removed to reduce weight, and the bomb-bay doors had to be adapted.
At the same time,
were trained in the use of a special bombsight, the
(SABS). For accuracy, multiple corrections had to be made for temperature, wind speed, and other factors. It was only effective if the target could be identified, and several missions were cancelled or unsuccessful because of difficulty in accurately identifying and marking the targets.
For use on underground targets, the bomb was fitted with three separate inertia No. 58 Mark I Tail Pistols (). These triggered
after a pre-set delay, which gave the bomb sufficient time to penetrate the target before exploding. Depending on mission requirements, the time delay could be set to 30 seconds or 30 minutes after impact.
To guarantee detonation, a total of three separate Type 47 long delay
were fitted inside the rear of the bomb. This dramatically improved relia even if two of the fuses failed to function, the third would trigger detonation. Despite this elaborate system, at least one Tallboy failed to explode during the second attack on the
dam and was found during repairs in late 1958 when the reservoir was emptied.
The bomb was aimed at the target during an operation and proved capable of penetrating deep into hardened reinforced concrete when it hit. This, however, was not the primary intention of Barnes Wallis's design. The bomb was designed to make impact close to the target, penetrate the soil or rock beneath or around the target, and then detonate, transferring all of its energy into the structure, or creating a
(cavern or crater) into which the target would fall.
This 'earthquake' effect caused more damage than even a direct hit that penetrated the armour of a target, since even a burst inside a bunker would only damage the immediate surroundings, with the blast dissipating rapidly through the air. An earthquake impact shook the whole target, and caused major structural damage to all parts of it, making repair uneconomic. The attack reports below should be considered with this in mind.
An alternative technique was to arrange detonation depth so that the crater broke the surface—useful for attacking railway marshalling yards and similar targets. The Tallboy produced an 80 ft crater with depths up to 100 ft, unlike conventional bombs which would produce many shallow craters across a target—each one of which could later be filled in rapidly with earth-moving equipment. Such a huge hole was time- multiple trucks and bulldozers could not be fitted around the periphery of the hole to speed the process.
The construction of each Tallboy was
because each was largely hand-made, requiring much manual labour during each separate manufacturing stage. The materials used were costly, with very precise engineering requirements with regard to casting and machining. For example, to increase penetrative power, a large and specially hardened steel plug had to be precisely machined and mated to a recess in the nose of the bomb. The
had to be machined into a perfectly
shape to ensure optimum aerodynamic performance. This was no easy task when manipulating a bomb casing with the size and weight of a Tallboy.
filling was poured by hand into the base of the upturned casing after melting it in "kettles". The final stage of explosive filling required that a one-inch layer of pure
be poured over the Torpex filling, followed by sealing the base with a 4-inch (100 mm) layer of woodmeal-wax composite with three cylindrical recesses fitted with the
and into which three chemical time-fuses were inserted when the bomb was finally armed.
Tallboys were not considered expendable, and if not used on a raid were to be brought back to base rather than safely
into the sea. The value of the weapon offset the additional risk to the aircrew.
Given their high unit cost, Tallboys were used exclusively against high-value strategic targets that could not be destroyed by other means. When it was found that the Lancaster could be modified to carry a bomb larger than the Tallboy, Wallis produced the even larger .
Six Tallboy bombs in a bomb dump at
prior to being loaded on
aircraft in October or November 1944
rail tunnel—The sole operational north-south route on the Loire. Nineteen Tallboy-equipped and six conventionally equipped Lancasters of 617 Squadron attacked on the night of 8–9 June
Squadron were guided on to the target by 83 Squadron Pathfinder Force. This was the first use of the Tallboy bomb and the line was destroyed—one Tallboy bored through the hillside and exploded in the tunnel about 60 ft (18 m) below, completely blocking it. No aircraft were lost during the raid.
was a set of offensive and defensive measures that were carried out to deal with the threat of the German
("buzz bomb" or "doodlebug") and
weaponry. As part of the operation, Tallboys were deployed on a number of sorties by the British to destroy several missile sites.
19 June 1944 –
The nearest Tallboy dropped by 617 Squadron landed 50 yd (46 m) from the target, a heavily fortified V-2 launch site under construction The bunker was rendered useless.
24 June 1944 –
The target was a V-2 assembly and launch site linked with the Watten site. Several Tallboy hits undermined the foundations but did not penetrate the dome. The bunker was abandoned.
25 June 1944 –
Lancasters of 617 Squadron scored three direct hits with Tallboys without loss.
Damage to the
from Allied air attacks, including attacks with Tallboy bombs.
4 July 1944 –
617 Squadron used seventeen Lancasters with Tallboys, supported by one
and one , in an attempt to collapse the
roof of the caves used as storage depots. Aircraft from No 5 Group followed up with 1,000 lb (450 kg) bombs.
6 July 1944 –
Attack on V-weapon targets. Damage was unknown at the time, and . In September,
found galleries blocked with earth and debris where Tallboys had hit one of the shafts. The V-weapon was revealed to be the .
17 July 1944 –
Sixteen Lancasters, led by a Mosquito and a Mustang, bombed Wizernes – three Lancasters managed to drop Tallboys (one caused the dome to shift out of alignment, two others blocked the entrance).
27 July 1944 – Watten
One Tallboy hit the target but did not penetrate the structure.
31 July 1944 –
Both ends of the railway tunnel were collapsed by Tallboys dropped by 617 Squadron. 's Lancaster at 3,700 m (12,000 ft) was hit by a 'friendly' Tallboy dropped from 5,500 m (18,000 ft).
Shipping in the English Channel and the Atlantic Ocean were threatened by
stationed in France. U-boat docks were protected against conventional aerial bombardment by thick concrete roofs.
14 June 1944 –
Part of the first massive RAF daylight raid since the end of May 1943, two waves attacked e-boat facilities at Le Havre: No 1 Group first, No 3 Group second. Just before the first wave, 22 Lancasters of 617 Squadron and 3 Mosquito marker aircraft attacked, several hits were scored on the pens, one bomb penetrated the roof.
15 June 1944 –
297 aircraft: 155 Lancasters, 130 , 12 Mosquitos, of Nos 1, 4, 5, 6 and 8 Groups attacked Boulogne harbour. One Halifax was lost. A French report described the great destruction as the worst raid on Boulogne. During the raid 22 Lancasters of No. 617 squadron bombed the e-boat pens with Tallboys. Due to cloud cover ten planes returned to base with their bombs. However the raid was considered a success as the e-boats retired to IJmuiden on the Dutch coast where they were better protected but less able to interfere with naval traffic supporting the Normandy invasion.
5 August 1944 –
15 Lancasters of 617 Squadron attacked the U-boat pens at Brest and scored six direct hits with Tallboys penetrating the concrete roofs. One Lancaster was shot down by flak. Subsequent attempts to reinforce other sites with even thicker concrete diverted resources from other projects.
6 August 1944 –
Flight Lieutenant Thomas Clifford Iveson dropped one Tallboy, bomb failed to penetrate base.
7 August 1944 –
The planned Tallboy mission against the U-boat pens was cancelled, Instead Keroman Submarine Base was the primary target.
8 August 1944 –
Flight Lieutenant Thomas Clifford Iveson dropped one Tallboy.
28 August 1944 –
Flight Lieutenant Thomas Clifford Iveson dropped one Tallboy.
23/24 September 1944 –
near , north of
During the night attack 617 Squadron scored six direct hits with Tallboys.
7 October 1944 –
The dam waters could have been kept in reserve to flood the area of a US advance. The Dambusters destroyed the lock gates with Tallboys dropped at low level, releasing the stored water.
15 October 1944 –
This target of the original Dambusters raid survived a second attack by 9 Squadron (617 Squadron did not participate in this raid). The Tallboy bombs were seen to hit the dam but did not breach it.
was a threat against convoys sailing to and from the Soviet Union.
15 September 1944 – ()
One Tallboy hit near the bow of the Tirpitz, passing through the
and hull, and exploded in the water on the starboard side of her . The blast wrecked the bow, and left the battleship's forward compartments flooded with 2,000 tons of water. The explosions of several other Tallboys in the water near Tirpitz also buckled some of her hull plates and . Five men were killed and fifteen wounded. Tirpitz was rendered unseaworthy and the damage was assessed as needing nine months' worth of work to repair, but this was considered unfeasible so the battleship was relegated to a floating artillery battery.
29 October 1944 – ()
Due to cloud coming in just before the attack, 32 bombs were dropped "blind". No direct hits were scored but one near miss bent a propeller shaft.
12 November 1944 – ()
In the final operation the Tirpitz was sunk when three Tallboys hit it, and several others fell close by. Several bombs landed within the anti-torpedo net barrier and caused significant cratering of the seabed, removing much of the sandbank that had been constructed to prevent the ship from capsizing. One bomb penetrated the ship's deck between turrets Anton and Bruno but failed to explode. A second hit
between the aircraft catapult and the funnel, completely destroying the entire section of belt armour abreast of the bomb hit and blowing a very large hole in the ship's side and bottom, causing significant flooding and a port list to 60 degrees. A third bomb struck the ship on the port side of turret Caesar, eventually leading to a magazine explosion that caused the ship to capsize.
The 11 foot thick concrete roof of submarine bunker "Fink II" in Hamburg, after having been penetrated by a Tallboy in early April 1945
Bombing of
pens, December 1944 – April 1945
15 December 1944 – IJmuiden on the Dutch coast,
617 Squadron attacked U-boat pens with Tallboys. A smoke-screen hindered the bombing, and the results went unseen.
12 January 1945 –
"32 Lancasters and one Mosquito of Nos 9 and 617 Squadrons attacked U-boat pens and shipping in Bergen harbour. Three Lancasters of 617 Squadron and one from 9 S the Germans told the local people that 11 bombers had been shot down. A local report said that three Tallboys penetrated the 3 1/2 -metre-thick roof of the pens and caused severe damage to workshops, offices and stores inside".
3 February 1945 – IJmuiden &
36 Lancasters of No 5 Group attacked U-boat pens at IJmuiden (9 Squadron) and Poortershaven (617 Squadron) with Tallboys. Hits were claimed on both targets without loss.
9 April 1945 –
617 Squadron attacked with Tallboys and . Some of the bombs hit their target and no aircraft were lost.
18 April 1945 –
969 aircraft: 617 Lancasters, 332 Halifaxes and 20 Mosquitos of all groups bombed the naval base, airfield and town "almost into crater-pitted ". Three H the islands were evacuated the following night.
19 April 1945 – Heligoland
36 Lancasters used Tallboy bombs against coastal positions.
8 December and 11 December 1944
The , (30 miles (48 km) south west of ) was attacked to prevent it being used to flood the area as American troops advanced. The lip of the dam was damaged, but the Germans prevented further damage by lowering the water level.
21 December 1944 –
617 Squadron.
14 March 1945 –
The viaducts were attacked by 617 and 9 squadrons with Tallboys and the first . The Arnsberg viaduct withstood the attack but 100 m (330 ft) of the Bielefeld viaduct collapsed through the 'earthquake effect' of the Grand Slams and Tallboys.
15 March 1945 – Arnsberg viaduct
The Arnsberg viaduct was attacked again by 9 Squadron. It did not collapse.
16 April 1945 –
The Lützow was attacked by 617 Squadron. Despite intense flak, 15 aircraft managed to bomb the target with Tallboys or with 1,000-pound (450 kg) bombs. One near miss with a Tallboy tore a large hole in the bottom of the Lützow and she settled to the bottom in shallow water. One Lancaster was shot down, the Squadron's last loss of the war.
25 April 1945 –
Hitler's vacation home, the Berghof, near
was attacked with a mixed force that included six Lancasters of 617 Squadron dropping their last Tallboys. The bombing appeared to be accurate and effective.
The latter of the
– was designed to be able to carry a bomb load that could include a load of two Tallboys internally, or one
plus assorted smaller weapons.
The T-10 was an American-made version of the 12,000 pounds (5,400 kg) Tallboy modified to use standard American components. Development was started in late 1944 and plans were made to drop them on the fortified island strongholds of the
to aid in softening their defences before amphibious assaults. None were ever used in combat, since the capitulation of Japan following the
negated their need. In the late 1950s the T-10 was re-designated the . During the Korean War a number of T-10s were converted to the radio-guided
bomb and were dropped by
to destroy railroad bridges and reservoir dams.
After the Korean War ended and the B-29 and
bombers were retired, the
no longer had an aircraft that could drop the M-121, and the bombs were put in storage. Production of the T-10 ended in 1955. The B-36 was the last operational aircraft that could drop a fully assembled Tallboy type bomb in the conventional way. During the Vietnam War, some M-121s, minus their rear streamlined shrouds and tail fin assemblies, were shipped to Vietnam for Commando Vault missions where the warheads were incorporated into the
weapons dropped by C-130s using radar control. The warheads were mounted on a platform and pulled by parachutes from the rear loading ramp of C-130s. After clearing the aircraft the large extraction chutes and pallets were cut away and small triangular chutes stabilized the large warhead until impact. A three-foot nose probe detonated the bomb at the correct stand-off distance. One of the last of the World War II Tallboy designs was dropped during a Commando Vault mission to clear a landing zone for helicopters on a ridge during the 1969
in Vietnam. Dropping from 3,000 metres (10,000 ft), the bomb hit exactly where it was needed. The Commando Vault missions were more accurate in bomb delivery on target than the more modern B-52s.
Work still progressed on the 43,000 lb (20,000 kg) , which could be carried by the A.
The B-52 bomb bay lacked the length required to load a Tallboy.
The use of any type or make of the Tallboy ended with the Vietnam War. None were dropped during the Gulf War in 1991 as none were in storage for the USAF. The large bombs dropped by C-130s during the Gulf War in 1991 were of the 6,800 kilograms (15,000 lb) type .
30 August 2005 at the .
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Dambusters.biz staff (2013), , , archived from
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Harris, Sir Arthur (2005) [1947], Bomber Offensive, Pen & Sword Military Classics, pp. 208, 218, 237, 252,  
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as holders of the copyright on the Operational Record Book (Page 507).
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McGowan, Sam (USAF-ret.) (October 1988), "Mission Commando Vault", Air Combat: 64–68,  
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; Johnson, H Taylor, Chris (2008). German V-Weapon Sites 1943–45. Oxford: Osprey Publishing.  .
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Wikimedia Commons has media related to .
] (in German)
Popular Mechanics, February 1945, p. 49.
RAF strategic bombing during the Second World War
aircraft weapons of
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