Photo By Lori Stewart | Sketch of organized defenses—Manning Mountain area, 19 July 1945... read more read more
by Mike E. Bigelow, INSCOM Command Historian
20-21 JULY 1945
From 20-21 July 1945, soldiers from Brig. Gen. Kenneth Althaus’s SPHINX Detachment intensively patrolled an area in northern Camp Hood, Texas. These patrols were part of a larger exercise to develop “the best combined arms technique for the use in the attack of Japanese field fortifications.” Lt. Col. Charley P. Eastburn, Althaus’s S-2, specifically examined how aerial and ground reconnaissance could support the effort.
As World War II came to an end in Europe, the Tank Destroyer Center at Camp Hood shifted its focus to supporting the fighting in the Pacific. In the battles on the Philippines and Okinawa, American soldiers suffered heavy casualties as they assaulted Japanese strongholds that had been adroitly integrated into existing terrain. Brig. Gen. Alexander O. Gorder, the center’s commander, and his staff concluded tank destroyers with their high-velocity and accurate main guns could help alleviate the situation. By late May 1945, Gorder had established a group—dubbed the SPHINX Detachment—to begin training tank destroyer crews to work with infantry teams. Within a month, however, the Army directed the group to broaden its scope to include air, armor, artillery, and engineers in developing ways to reduce Japanese defenses.
The 50-year-old General Althaus assumed command of the SPHINX Detachment and oversaw the ensuing exercises. A career infantryman, Althaus had commanded one of the 10th Armored Division’s combat commands in Europe before returning to the U.S. While his staff came from the Tank Destroyer Center, his 3,500 troops came from other training centers. These troops were combined in a composite regiment—the 53d Infantry—of one infantry battalion and two field artillery battalions, with tank, tank destroyer, engineer, and ordnance companies. Col. Stephen S. Hamilton, a combat veteran from the Pacific, commanded the regiment. The two officers quickly went about building a cohesive team, emphasizing how the SPHINX Detachment’s effort would undoubtedly save many American lives by developing more successful methods to overcome Japanese defenses.
For the exercise, Gorder and Althaus decided to use the Manning Mountain area of north Camp Hood. The area’s finger-like ridges and hills were topographically and geologically similar to parts of Japan. On this terrain, German prisoners of war prepared more than 3,000 positions and thirty-five large caves to represent a reinforced Japanese infantry regiment’s stronghold.
The exercise was divided into five phases. Beginning on 6 July, the 3d Tactical Air Command flew aerial reconnaissance missions over the area. These missions continued throughout the exercise. For two days (15-17 July), the air command’s planes bombed the area to evaluate its effectiveness in destroying the defenses and defoliating the area. During the next two days (18-19 July), Col. Hamilton’s artillery and engineers tested various methods to defoliate parts of the area. From 20-21 July, the infantry conducted day and night patrols to feed the G-2 information necessary to plan a coordinated attack. After each of these phases, Althaus’s control officers evaluated the results against the actual effects so the air-ground team could use the best techniques in the final combined arms test phase during 22-24 July.
For his part, 33-year-old Colonel Eastburn, an infantryman with tank destroyer experience, examined the accuracy of the aerial and ground reconnaissance activities. Although the photo interpreters uncovered many of the caves and strongpoints, Eastburn’s staff discovered the analysts found less than 15 percent of the smaller mortar, machine-gun, and anti-tank emplacements. Nevertheless, the S-2 believed aerial photos were useful and recommended overprinted photomaps showing enemy defenses be distributed “in sufficient quantity and early enough to permit detailed study by platoon leaders prior to an attack.” In particular, oblique aerial photos proved useful in orienting daylight patrols to the ground they would cover. “Thorough reconnaissance,” the final report noted, “by all agencies over an extended period of time [was vital] to detect and locate caves and other defensive installations.”
Immediately after the Sphinx Detachment completed its exercise, the Army had writers begin working on a training circular, entitled Reduction of Japanese Field Fortifications, to capture the techniques developed during this test. While Japan surrendered shortly after its publication, the test revealed “the terrific hitting power achieved when all arms were integrated in action.”
----
"This Week in MI History" publishes new issues each week. To report story errors, ask questions, or be added to our distribution list, please contact: TR-ICoE-Command-Historian@army.mil.
| Date Taken: | 07.14.2023 |
| Date Posted: | 07.14.2023 19:12 |
| Story ID: | 449274 |
| Location: | US |
| Web Views: | 116 |
| Downloads: | 0 |
This work, Project Sphinx Tests Methods to Reduce Enemy Defenses (20-21 JUL 1945), must comply with the restrictions shown on https://www.dvidshub.net/about/copyright.
No keywords found.
