Flightdeck Friday: Skipbombing and The Bismarck Sea
OK – so this week we’re doing something a little different by going Joint (before Joint was cool, so to speak). During the Midway postings, a commenter (commentator?) asked if YHS would provide a little more on skip bombing. Since 5th AF pretty much originated the tactic for counter-ship attacks (ASUW) and had such success with it in the SW Pacific AOR, we figured it was only right to give them their appropriate due on these pages. And no, you won’t get credit for JPME (but you could always ask your instructor…)
It’s early 1942 and you are inbound to Douglas MacArthur’s staff as his new air commander, commanding the Fifth Air Force and the Allied Airforces in the South West Pacific. The dilemma you are faced with is that the allies have been in retreat in the face of the Japanese onslaught which has seen great swaths of Asia fall into their possession. You, in turn, are to meet that formidable force with a rag-tag group of survivors gathered from around the Philippines and the rest of the theater, now based in Australia. Your counterpart over in the Navy is exceptionally busy as well, struggling to meet the threat with what was still afloat from Pearl Harbor and subsequent attacks (fortunately the carriers survived) and some land-based air. Most of it, however, is out of your territory and besides, controlled by the Navy.
You think about where and how to hit the enemy to effect the most damage, and like your Navy counterparts, deduce that the Achilles heel in the Empire’s far-flung lines of support is shipping, merchant shipping. The thousands of island garrisons, from the biggest at Rabaul to the smallest outcrop of coral and volcanic rock were all heavily dependent on supply from the sea. In later parlance, it would be “a target rich environment.” Problem is, pre-war tactics have proven abysmal when applied in the real world. High altitude precision bombing wasn’t working against a maneuvering target and attempts to replicate at lower altitudes ran into swarms of fighters and heavy flak from escorts. What do you do?
If you’re George C. Kenney, you do the following. Before departing for the Pacific, you determine that because of the ranges involved you need long-legged fighters to provide some protection for the medium- and heavy-bombers you intend to unleash. So you get “Hap” Arnold to assign 50 P-38s with 50 pilots from the Fourth Air Force to your new command in the Pacific, making sure that a certain aggressive young lieutenant who had looped the Golden Gate, Richard Ira Bong, would be one of those pilots.
You also request some 3,000 parafrag bombs to be sent to Australia, where you think they might come in handy against the Japanese, especially in airfield and port services denial. While en route to Australia with your aide, Major William Benn, in July, you discuss the shortcomings of pre-war bombing tactics and turn to low-altitude bombing. During a layover at Nandi in the Fijis, you requisition a Martin B-26 Marauder bomber and test a theory–that a bomb could be made to skip along the water like a stone. Your theory proves to be correct and the technique of skip-bombing is born.
Upon arrival in theater you institute several plans that would have a revolutionary effect on combat operations. To begin with, you take the rudimentary transport aircraft under your control and layout the beginnings of air transport support for ground operations. You assemble an air force out of damaged aircraft on hand and requisition aircraft not in favor in Europe (and therefore available) – aircraft like the B-25, A-20 and P-38. You turn over your tactics and operational planning and execution to the likes of leaders like:
Maj William Benn, CO of the 63rd Bomb Squadron who developed and refined the art of skip-bombing. He experimented with different bomb sizes, timed fuses, and approaches to targets. He led one skip-bombing raid with a half-dozen B-17s at low altitude and sent six enemy ships to the bottom. According to Kenney, “Skip bombing became the standard, sure way of destroying shipping, not only in Bill’s bombardment squadron but throughout the Fifth Air Force.” In skip bombing, the bombing aircraft flew at very low altitudes (200 to 250 feet above sea level) at speeds ranging from 200 to 250 miles per hour. They would release a “stick” of two to four bombs (usually 500 or 1000-pounders) equipped with four- to five-second time delay fuses at a distance of 60 to 300 feet from the side of the target ship. The bombs would “skip” over the surface of the water in a manner similar to stone skipping and either bounce into the side of the ship and detonate, submerge and explode under the ship, or bounce over the target and explode as an airburst. All outcomes were found to be effective.
Maj “Pappy” Gunn who had already displayed a legendary skill at aircraft maintenance on a shoe-string. Gunn developed a package of four .50-caliber machine guns for the nose of A-20 light bombers. This impressed Kenney. He directed Gunn to “pull the bombardier and everything else out of the nose of a B-25 medium bomber and fill it full of .50-caliber guns, with 500 rounds of ammunition per gun.” Kenney said, “I told him I wanted him then to strap some more on the sides of the fuselage to give all the forward firepower possible. I suggested four guns in the nose, two on each side of the fuselage, and three underneath. If, when he had made the installation, the airplane still flew and the guns would shoot, I figured I’d have a skip bomber that could overwhelm the deck defenses of a [Japanese] vessel as the plane came in for the kill with its bombs. With a commerce destroyer as effective as I believed this would be, I’d be able to maintain an air blockade. . . anywhere within the radius of action of the airplane.”
Maj. Ed Larner. He and his “commerce destroying” squadron had become expert at skipping bombs into ground targets at low altitudes and strafing the nose- and side-gun-firing .50 calibers. Kenney recalled, “I saw a couple of them practicing on the old wreck on the reef outside Port Moresby. They didn’t miss. It was pretty shooting and pretty skip bombing.”
These efforts led to signatory events, such as the Battle of the Bismarck Sea in March 1943:
Higher res map here.
In early 1943, the Japanese army in New Guinea launched an offensive with the 51st Japanese Division advancing on Kanga Force – the Australians holding the airfield at Wau. To achieve this objective, the 51st required reinforcement from Japanese forces in Rabaul. These reinforcements were to sail around New Britain through the Bismarck Sea and across the Huon Gulf to Lae.
February 19th, allied forces intercepted message traffic indicating the Japanese were marshalling their forces and preparing to embark a New Guinea-bound troop convoy from Rabaul. Almost 7,000 Japanese infantry and marines were to travel to New Guinea in eight crowded troop transport ships. Surveillance patrols increased and the Allies readied their air forces.
By early March, a combined US/Australian force of 154 fighters, 34 light bombers, 41 medium bombers and 39 heavy bombers had been assembled. At 1500 local on 1 March a patrolling B-24 Liberator spotted a convoy through a break in the clouds. US heavy bombers were immediately dispatched to attack, but failed to find the convoy due to heavy cloud cover. The following day brought clearer skies allowing a progression of attacks from B-17s attacking from medium and low altitude, including using ski-bombing techniques. Several hits were scored with one sinking claimed at the loss of one B-17 due to fighters.
The following day, March 3rd, the convoy was within range of the RAAF bomber squadrons at Milne Bay in Papua and they attacked and they were joined later by the US and Australian squadrons from the vicinity of Port Moresby (they were held on the ground due to weather). The first attack was made by RAAF Beaufort torpedo bombers. They did not score any hits but were followed closely by 13 RAAF Beaufighters who inflicted damage with low level strafing runs until B-25 Mitchell’s of the 5th USAAF attacked from altitudes of 2,000 to 3,000 feet.
The nexus of the attack though came with the modified B-25s which had been practicing skip-bombing – the impact was devastating as they claimed 17 hits. Above them , B-17s bombed the convoys from high altitudes, disrupting the convoy and making defensive fire difficult at best. By this time half of the transport ships were lost or are sinking.
The final phase of the battle saw a combined attack with A-20’s and B-25’s at low level while counter-air operations were conducted against the Japanese airfield at Lae to thwart attempts at air cover for the convoy. All told, another 15 hits were claimed. That evening, US Navy torpedo boats sank the remaining transport. By dawn of March 4th, all eight transports were sunk along with four of their escorting destroyers (the other four were badly damaged). Out of 6,900 troops who were badly needed in New Guinea, only about 800 made it to Lae. Few were battle ready and most had lost their weapons and equipment.
Note the inbound bomb just ahead of the skip-splash…
Great history lesson. I have seen a documetary on TV about a simiilar technique the British used on a dam during WWII. Thought they had originated the technique.
As a kid I always thought that all those .50s in the nose were “cool”. Now they make much sense, suppressive fire for way crazy low runs.
Nothing wrong with “firepower forward.” Great reading…
❗ Thank you VERY much for your piece on the Battle of the Bismark Sea. My father was in the 43rd heavy bomb group out of Seven Mile (airstrip seven miles from Port Morseby). A “Lucky Dicer”. He was an engineer – top turret gunner in that battle. I heard a lot about those three days. Most of his missions were in 17s and 24s before he rotated back to Arizona as an instructor.
I especially enjoyed your drawing of the 43 bomb groups’ B-24s. I pay attention for pictures from Seven Mile or of the 43rd. Never saw that one before. I think I remember almost everything he told me about the different missions.
I read many articles and reports about Port Morseby, Seven Mile, the Fifth, Ken’s Men. Something basic and essential to the true story, that photograph in time, is always missing. What is missing is the demoralizing effect that a 20% casualty rate per mission had on crews. My father said ships and crews just “disappeared. No one saw them go down because they were so busy covering their “cones of fire”.
Once only his B-17 returned from Raubul out of a flight of three. He only had fighter escort once and rarely more instruments than an untrustworthy compass. Many of the ships were war weary. Not many were flight worthy at any given moment. He said that at times a “maximum effort” meant 13 to 16 ships when they had 64 on paper.
My father said he didnt want to know anyone’s name because crews only lasted a few missions. When my father was in his eighties he still suffered nightmares four to five times a week. The nightmares were actual memories, not imagination.
I have a picture of my father and his crew standing on Marston mat, under the B-17, “Georgia Peach”. There are only nine crew in the picture because a few hours earlier their tail gunner was killed over Raubul. My father was in another B-17 when he saw the “Georgia Peach’ take cannon fire into the cabin and plunge trailing smoke into the sea without any parachutes.
My father loved the B-17s because they always carried him home. Once they took a naval shell through th wing over Raubul. It blew a big hole in the wing and completely took out the landing gear on that side. They ground looped at Seven Mile but walked away. They were forced to do many things Boeing said a B-17 just could not do. They took off so overloaded with bomb and gas that if one engine ‘just coughed” they went in. He said he remembered waiting, several times, for bombs and ammo to ‘cook off” from the aircraft ahead of him in line to take off that did not clear the treeline and went in.
He went with me when I rode in a B-17 that visited our local airport. I stood in the top turret and had a fabulous view of four purring radial engines. He told me how he stood in that top turret as the sun came up the morning of the second day of the Bismark Sea. They were sent to kill a crippled japanese destroyer. At wavetop height they “emergency salvo”ed the whole load into the side of the ship. He could see sailors in white and marines in khaki on the deck. He wondered if they were going to clear the superstructure they were so low. They broke the ship in half. One piece went down immediately ant the other bobbed on its side.
Thank you for your piece on the Battle of the Bismark Sea and mention of the 43rd heavy bombardment group.
My father was Tech Sgt James B. Warren.
DonWarrenLaw@Verizon.Net
How about giving credit to the artists who’s paintings you use here?
THIS SKIP BOMBIN’ WOULD HAVE WORK WELL AT THE BATTLE OF MIDWAY, BUT THOSE AIRMAN DID ALRIGHT WITHOUT IT. THEY COULD HAVE USED THESE B-25 GUNSHIPS DURING THE D-DAY INVASION. THEY COULD TORN UP THE BEACH BEFORE OUR TROOPS ARRIVE, SAVING MANY. TRY TO READ ANYTHING ABOUT THE BISMARK SEA. MANY THANKS TO A JOB WELL DONE.