|Army engineers installed two temporary bridges over the Khazir River on the highway between Mosul and Irbil last April. They were removed following repairs to the permanent bridge, which had been bombed during the fighting.|
The U.S. Armys 130th Engineer Brigade reached two significant bridging milestones in mid-January during the unit's final days of deployment in Iraq. In one case a landmark assault float bridge its troops emplaced during fighting in April was removed, and in the other, an inadvertent bridge equipment destruction test came to an end.
On Jan. 15th, Engineers under the 4th Infantry divisions 74th Multi-Role Bridge Co., out of Fort Hood, Texas, removed The Birthday Bridge at Tikrit, the longest assault-float bridge placed under combat conditions since World War II.
The Birthday Bridge was built by the 130ths 565th Engineer Battalion, headquartered in Hanau, Germany, on April 28, Saddam Husseins birthday. The bridge spanned the Tigris in his hometown, just downstream of a bridge that had lost one of its two lanes in a bomb strike. We figure he might have even been watching us through binoculars from his spider hole, joked the 130ths commander, Col. Gregg Martin. Saddam Hussein was captured on Dec. 13 in a hideout nearby. Together with almost 265 meters of temporary causeway, the armys 300 meters of floating bridge allowed two-way traffic to resume over the river at Tikrit.
Repairs have yet to begin on the damaged fixed bridge, but the engineers took up the assault float bridge because they have replaced it with a 350-meter, 7-span Mabey Johnson Bridge on floats further downstream, maintaining a one-way traffic loop into and out of the city. The new pontoon-supported bridge requires less maintenance and security.
Bechtel is expected to begin repairing the permanent Tikrit bridge soon.
In the other project, engineers from two units, one under the 130th and the other the 74th MRBC under the 4th ID, removed of a pair of temporary spans over the Khazir River on a highway connecting Mosul and Irbil on Jan. 16. The project had turned into a side-by-side destruction test of the two kinds of bridging equipment. Removal was enabled by the completion of repairs to two-lane twin of the bridge that stands beside the temporarily patched structure.
The temporary bridges were placed at the end of April after aerial bombs cut both the crossings twin concrete bridges during last springs fighting.
Engineers patched one bridges section of missing deck with a Medium Girder Bridge (MGB) unit, a structure designed for manual assembly that is cantilevered across gaps with considerable might and brawn. The lane beside it on the same structure was bridged with a Heavy Dry Support Bridge (HDSB), a new product designed for placement by its own truck-mounted crane. It requires a far smaller crew to install. The project marked the armys first use of the HDSB in combat.
The arrangement established two lanes of traffic, one in each direction, on one of the parallel, two-lane bridges. The other cut bridge was left untouched for repairs that army engineers expected Bechtel to begin in June. Bechtel was delayed, however, and meanwhile the temporary bridge units endured very heavy traffic of at least 1,000 vehicles a day, says Staff Sgt. Brett Bybee, the bridge liaison on the 130ths headquarters staff.
|The 130th Engineer Brigade commissioned the so-called Birthday Bridge in Saddam Hussein's hometown of Tikrit on April 28, 2003, on the deposed dictator's 65th birthday.|
Neither bridging unit is designed for long-term use. Specifications call for inspection every 1,000 vehicles because pinned connections, drop-in deck panels and other features that make them portable can be loosened or distorted through heavy use. By October 12, with both bridges suffering considerable wear, the HDSB was replaced by another of the same design, while the MGB was patched up with replacement parts that stretched its life for another month before it too had to be changed out by another MGB.
In their last mission before heading home, with permanent repairs on the bridge next door complete, engineers from the 459th Multi-Role Bridge Company, a reserve unit headquartered in Bridgeport, W. Va., removed the MGB. The other temporary bridge was taken up by the 74th MRBC.
The army is studying the failure modes of the two bridge units, but declines to release specifics, citing strategic considerations.
(Photos courtesy of US Army 130th Engineer Brigade)