| Original caption: “On January 27, 1945, B-24 Liberators of the Seventh Bomb Group, operating under Major General George E. Stratemeyer’s Allied Eastern Air Command, knocked out three bridges on the important Moulmein-Ye rail line over which the Japanese attempted to carry a large proportion of supplies for the troops on the Burma fronts. Here is one of the bridges, thirty-five miles south of Moulmein, before the attack. As the B-24s leave the target, the bridge is completely destroyed, and the track on both approaches lies twisted and broken.” With the United Kingdom Royal 14th Army’s advance into Burma following the crushing defeat of the Japanese at Imphal, and a strong likelihood that this advance would continue all the way to Rangoon in 1945, the Allied Strategic Air Force under Major General George E. Stratemeyer (November 24, 1890 – August 9, 1969) concentrated on breaking Japanese lines of communication in southern Burma, Thailand, and Malaya. Bridges became a vital target in this campaign, for every time 1 was destroyed or damaged along the extensive single-track railway lines into Burma, traffic ground to a halt. The more bridges that could be knocked down, and for longer periods, the greater the disruption to the flow of supplies to the retreating Japanese armies. Bridges were never easy targets. An analysis of the bombing effort during 1943 showed that the Consolidated B-24 Liberators had managed to achieve only 1 direct hit on a bridge for every 81 sorties, and these were targets that required direct hits; near misses did little damage to a bridge’s structure. The 7th Bomb Group would resort to medium and low-level attacks, new tactics, and a new weapon in its offensive against bridges in Thailand and Burma. The 1st operation against bridges was a volunteer mission on November 1, 1944, to bomb the Ban Dara Bridge in central Thailand, located on the line between Bangkok and Chiang Mai. The Japanese Army had been steadily building up the flow of supplies along this northern route as an alternative to the main line, which ran west from Bangkok to Burma. 4 aircraft, 1 from each squadron, attacked the bridge an hour before sunset, each Liberator making individual runs at 300 feet (90 meters) and dropping 2,000-pound (450-kilogram) bomb on each run. After 3 aircraft had finished their bomb runs, the bridge was still standing. Lieutenant James L. Nemecek, Junior (April 29, 1917 – February 15, 1998), of the 436th Bomb Squadron came in to make his last run and hit 1 of the bridge’s main concrete piers with 3,000-pound bombs, dropping the 800-foot (240-meter) bridge into the river below. While the 9th and 493rd Bomb Squadrons withdrew from operations for 2 weeks to undergo intensive training in low-level attacks, the 436th and 492nd Bomb Squadrons continued the campaign against the bridges, conducting several missions against structures on the Bangkok-Chiang Mai line with mixed success. The crews, bombing from different altitudes, would often see their bridge target completely covered with explosions, only to find that it was still standing when the dust and smoke cleared. Knowing that the bombers would have to come back, the Japanese moved machine guns to defend the Kaeng Luang Bridge, and on the repeat attack on November 21, shot down 1st Lieutenant Charles E. Mead’s (March 4, 1921 – November 21, 1944) aircraft B-24J #44-40811 as he ran in on the target at 300 feet, killing the entire crew. At the end of November, the 9th Bomb Squadron sent 12 and the 493rd Bomb Squadron sent 9 aircraft, respectively, to bomb Bridge 277 on the Bangkok-Moulmein railway line. This structure spanned the infamous River Kwai, and despite achieving a tight bomb pattern from 8,500 feet (2,600 meters), the bridge was left standing. The 9th Bomb Squadron tried again on December 13, in cooperation with the 436th Bomb Squadron. While the latter unit bombed the nearby flak batteries, the 9th sent in 12 aircraft from medium altitude and 2 at low level. The execution was flawless, but once again the bridge remained standing. It would be attacked so often that the structure would become known within the 7th Bomb Group as “Old 277.” After returning from his 4th or 5th mission to “Old 277,” 1 crewman ‘volunteered to parachute out and dynamite the damn thing.’” “Old 277” finally fell on February 13, 1945, when 4 B-24s from the 493rd Bomb Squadron, followed by 6 aeroplanes from the 9th Bomb Squadron, finally managed to bring the bridge down with a low-level attack at 300 feet. Part of the solution to the problem of bombing bridges came with the introduction of a new weapon, the Azon bomb. This was a 1,000-pound bomb with a radio-controlled tail fin that allowed the bombardier to maneuver the weapon after it had been dropped, correcting deflection errors in flight. A flare attached to the rear of the bomb enabled the bombardier to track its fall. Azon bombs were ideal for attacking the narrow bridges on the Burma-Thailand railway line in the clear weather of the dry season. In the autumn of 1944, 10 B-24s equipped for Azon bombing and 10 trained crews joined the 7th Bomb Group. Initially distributed among the 4 units, they were subsequently reassigned to the 493rd Bomb Squadron for ease of maintenance. The 1st Azon mission took place on December 27, 1944, when 6 aircraft attacked the Pyinmana Railway Bridge in Burma. 4 Azon bombs dropped on the middle span and knocked the southern span to a 45-degree angle, while 10,000-pound (900-kilogram) bombs landing within 100 feet (30 meters) of the bridge did little damage. On its 2nd Azon mission on December 30, the 493rd Bomb Squadron demonstrated the effectiveness of this new bomb. The group dispatched all 4 squadrons to bomb the Taungup-Prome Highway, with the 493rd Bomb Squadron carrying Azon bombs, and the other squadrons carrying 2,000-pound bombs. After demolishing 425-foot-long (100-meter) wooden trestle bridge with a combination of Azon and 2,000-pound bombs, the 493rd blew up a 75-foot (20-meter) long bypass bridge nearby, and then followed the 9th Bomb Squadron to another 150-foot-long (45-meter) bridge. The 9th failed to knock down the latter, so the 493rd came in and dropped it with Azon bombs in 2 runs. The unit then went to a 385-foot-long (117-meter) bridge near Taungup, and with only 4 Azon bombs left, knocked the bridge out with 3 direct hits. From then on, the 493rd Bomb Squadron concentrated on using the Azon bomb while the other units continued their attacks from medium and low level. As January turned to February, and February to March, the list of destroyed and damaged bridges grew longer. On March 19, 1945, the 7th Bomb Group flew a bridge-busting mission that earned the group its 2nd Distinguished Unit Citation. Some 37 B-24s from all 4 squadrons flew to the Kra Isthmus on the Malay peninsula, several 100 miles south of Bangkok, to bomb bridges on the Bangkok-Singapore railway line. The bombers carried 2 bomb-bay fuel tanks and 4,000-pound bombs each. The mission involved a 19-hour round-trip flight of 2,700 miles (4,340 kilometers), the 9th Bomb Squadron historian noting proudly that this was just 300 miles short of the longest Boeing B-29 Superfortress mission to date. The group knocked out several key bridges and bombed rail facilities. 1 crewman was killed, and 2 were wounded by flak, and an aeroplane ditched on the return flight when it ran out of fuel. In April 1944, Colonel Harvey T. Alness (November 19, 1909 – June 11, 1998), the commander of the 7th Bomb Group, introduced a new bombing technique using a glide-bombing approach. A similar tactic had proved extremely successful for the North American B-25 Mitchells of the 341st Bomb Group. The latter had discovered through a fortuitous accident that a form of glide-bombing with a sharp pull-up at the end of the glide could send a bomb directly into a bridge’s structure instead of it bouncing off as had happened in many low-level attacks. After considering the problem, Colonel Alness arrived at the same solution. Although the idea of using the Liberator as a dive-bomber seemed slightly insane to some, Colonel Alness had the 9th, 436th, and 492nd Bomb Squadrons go through a short but intensive training program in the new technique, using a mock-up of a 200-foot-long (60-meter-long) bridge. The pilot would approach the target along its long axis and then begin his glide at 1,500 feet (450 meters), descending in a 20 to 25 degree glide to release the bomb at 500 feet (150 meters) as he pulled out. A toggle switch was fitted to the control column, allowing the pilot to release the bomb using a special sight designed specifically for this purpose. The 7th Bomb Group attempted the new bombing technique on April 24, 1945. The mission that day was to destroy as many bridges as possible along the Burma-Thailand railway, with each squadron given a designated section of the line. The group sent out 41 aircraft, the 493rd Bomb Squadron with its Azon bombs, and the other 3 squadrons using glide-bombing. Up to this point, the 7th Bomb Group had destroyed 98 bridges with its combination of medium and low altitude attacks and the newer Azon bombs. The results on the April 24 mission were nothing short of spectacular, for at least 30 bridges were destroyed, and another 18 damaged, as well as large sections of railway track left buckled. Virtually every pilot sent out managed to destroy or damage a bridge. The cumulative effect of the Allied Strategic Air Force’s bombing campaign against the bridges put a severe strain on the enemy in Burma. Allied intelligence had estimated that the Japanese Army needed approximately 490 tons of supplies per day, with Japanese Army Air Force units requiring an additional 110 tons. By the early months of 1945, the combined efforts of the 7th Bomb Group and Royal Air Force Liberator units in the Strategic Air Force had reduced the daily tonnage over the railway lines into Burma to less than 150 tons a day. | |
| Image Filename | wwii1517.jpg |
| Image Size | 1,020.50 KB |
| Image Dimensions | 1718 x 2934 |
| Photographer | |
| Photographer Title | United States Army Air Force |
| Caption Author | Written or Adapted by Jason McDonald |
| Date Photographed | January 27, 1945 |
| Location | |
| City | |
| State or Province | |
| Country | Burma |
| Archive | National Archives and Records Administration |
| Record Number | NRE-338-FTL(EF)-2802(12) |
| Status | Caption ©2026 MFA Productions LLC Please Do Not Duplicate or Distribute Without Permission; Image in the Public Domain |
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