Blog 12/09/2020 - Chosin Reservoir - Bridge

MHT Blog December 9, 2020 - Chosin Reservoir – North Korea
My Division for a “Bridge Over Frozen Water”

The Main Supply Route (MSR) was a single road south from the Chosin Reservoir to Hungnam was cut when elements of the Communist Chinese Army’s (CCA) 60th Division destroyed the road bridge at the hydroelectric plant spillway south of Koto-ri near the Funchilin Pass. The Marines had repaired the gap twice before but the third effort produced a serious breach making escape impossible for the 1st MarDiv (Reinforced) or so the Chinese thought. General Song Shilun, CCA 9th Army Commander hoped that his remaining depleted forces, along with the blown bridge, would be enough to slow or even stop the 1st MarDiv and UN forces until he could bring fresh divisions from farther away to the Funchilin Pass.

LtCol Partridge, the 1st MarDiv Engineer Officer, had determined that the 16-foot gap couldn’t be repaired with materiel on hand but could be spanned by four sections of an M-2 steel "Treadway" mobile bridge. However, the Marines had no such bridge sections, but fortuitously there was a detachment of the Treadway Bridge Company from the Army's 58th Engineer Battalion at Koto-ri with two “Brockway” trucks that could carry the bridge sections if they could be delivered. MajGen Oliver P. Smith, the 1st MarDiv Commander contacted the Far East Combat Cargo Command to request an aerial delivery of the “Treadway” bridge sections were needed to repair the MSR, eight bridge sections were requested although only four were needed for that size gap.

After a dismal test effort, the parachute riggers configured eight Treadway Bridge sections with two large 48-foot diameter G-5 cargo parachutes, and loaded the 18-foot 4,000-pound items onto eight C-119s “Flying Boxcars” from the 314th TCG's 61st Troop Carrier Squadron. Three were dropped in a drop zone just north of Koto-Ri and the other five a mile south. Six of the eight bridge sections landed undamaged within the small UN drop zones, one was badly damaged and one drifted into CCA-controlled territory. The Chinese had a field day shooting at the planes with their rifles as they lumbered by as they had to come in low, flying flat and steady. All eight had numerous bullet holes when they returned to base after the drop. After the 7th Marines cleared the Funchilin Pass’s surrounding slopes of Chinese troops, the Army and Marine engineers moved up the remaining six bridge sections for installation. 

Only four sections were needed to repair the damage, but the sections weren’t usable by themselves. “Treadway” bridges are designed for vehicles with tracks, such as tanks, or for large trucks. They are laid out in pairs, side by side, with a gap between them making smaller vehicles such as jeeps and ambulances incapable of using them. A Treadway bridge could be made usable for smaller vehicles if lumber is used to fill in the gap between them. Luckily, lumber was available for this and the bridge was successfully repaired  by soldiers and Marine combat engineers by the morning of 9 December. The way was now clear to move south of the Funchilin Pass.