The 300th Engineers performed a variety of tasks. Building bridges and maintaining roads was their specialty. They were responsible for building bridges that either replaced what German engineers demolished or afforded access to a geographical location that was strategically advantageous to their mission. There were several types of bridges that were built by combat engineers and two main categories: Fixed and Floating bridges. The following is engineering terminology related to bridge building.

The fixed bridges included:

1. The Simple Stringer Bridge consisted of two abutments, a single span of stringers and a floor. (For spans between 15 - 25 feet in length)
2. The Bailey Bridge was the most famous and some are still in use today. It was fashioned from a prefabricated set of bridge trestle parts and was a free standing bridge erected piece by piece. Bridges varied for the tonnage that was expected to cross over the bridge. Although the British invented the structure for use in the First World War, it was modified to accommodate the increased tonnage of the new tanks and motorized infantry and artillery vehicles. In the United States, a partnership was created between the U.S. Army Engineers and several steel and component manufacturers who conferred with their British counterparts in order to enhance the manufacturing processes efficiency. The British and U.S. were equally concerned with "simplicity, weight and transportability." Bailey bridges were designed for spans up to 120 feet and able to carry up to 70 tons.
3. The Trestle Bent Bridge consisted of two or more stringer spans. The supports between the abutments were trestle bents.
4. The Light Portable Steel Bridge consisted of two trusses (assembled by manpower, in lengths up to 72 feet) supporting a one track timber deck.

Floating bridges were as follows:

1. The Light Ponton Bridge M1938 was a floating bridge capable of carrying 10-ton traffic in one direction.
2. The Heavy Ponton Bridge M1940, although similar to the light ponton, was much heavier and carried a 25 ton load.
3. The Steel Treadway Bridge was designed to carry medium tanks. It had steel treadways for runways, which were emplaced by means of a truck mounted crane. It used special rubber pontons.

For any kind of embankment, approach, or size of a river, there was a compatible bridge that could be deployed.

In addition to building the famous Tucker Bridge, a fixed wooden bridge in Carentan, the 300th constructed a four-section Treadway Bridge across the Douve river at Pont L'Abbe; another at Candoll, France and Menden, Germany and built a 288 foot floating Treadway Bridge across the swift moving Isar river at Moosburg, Germany. This bridge prompted General George S. Patton of the American Third Army to write a letter of commendation to the 300th Battalion Commander expressing his satisfaction and recognition of their spirit of teamwork.

The 300th Combat Engineer group maintained roads on the march into Germany. They cleared ice, snow and debris. They removed wrecked enemy tanks, vehicles and mines. Combat Engineers landed in Normandy already equipped with the knowledge and practical experience of laying roads. The 1,500 mile Alcan Highway from British Columbia, Canada to the heart of Alaska was not only an engineering marvel but continues to serve transportation needs. From its construction, the D-8 caterpillar tractor's capability became well respected and engineers learned how to invent new ways of laying roads quickly and in atypical terrain.

Combat engineers were trained how to use a multiplicity of tools: heavy and light. They were trained to use their hands and their creativity to solve urgent problems. Electricians, plumbers and specialists were drafted from civilian life but the majority of road builders were trained in places like Fort Belvoir in Virginia and Camp White, Oregon.

The 300th constructed roundabouts in Isigny and St. Sever Calvados, France. They maintained roads near Aachen and removed German tanks and wreckage near Reichersdorf, Germany. In January, 1945 they removed ice, snow and debris from roads while guarding bridges they might need to demolish. They even constructed the snow plows they needed to do the job.

The 300th also maintained directional signs on roads, reopened railroad lines, operated control terminals and supervised reopening of inland waterways. The activities of the 300th created the need for construction materials on demand and prompted them to establish gravel pits, lumber stock yards, operate twenty saw mills with a daily production of 35,000 board feet in Belgium and guard steel and tar plants in Leiden, Germany. All of these were related to their jobs of building and maintaining roads.

The Ponton with Treadway Bridges

The following is an account of the building of a ponton bridge with treadways placed on top. It was written by Randy Hanes of the 300th Combat Engineers, Company C "to graphically illustrate, with moderate praise, the type of activity and conditions that engineers had to meet and conquer."

The sign, in big, bold, red letters reads, "Built by Company C, Spirit Company 300th Engineer Combat Battalion. Equipment furnished by 998th Treadway Bridge Company."

The ponton bridge at Moosburg, Germany was built for General Patton's Third Army to cross the Isar River. The current was swift and vicious; faster than the Roer, the Elbe or the Danube and whatever was caught in its clutches drifted rapidly downstream either to be beached or sunk. The Isar River was an important link to the rapidly advancing front. The press, official photographers and Newsreel cameramen were there to capture the event while three generals (one, two and three-star) looked on as we assembled the two hundred eighty-eight foot floating span. Dozers had started breaching the earthen levee clearing the way for the launching ramp. There was seething activity everywhere. Crews were assembling the rubber floats, inflating them with the huge air compressors and a crane was lifting the steel treadways upon them (the pontons) as each section was floated into position. Guy lines were being secured to the blown wreckage that remained of the original bridge upstream. Infantrymen of the 395th Regiment, 99th Division, perilously walked its twisted trestles. Several tanks with their guns pointed beyond the far shore were standing by in an emergency position. Overhead, 155mm shells whizzed toward the forward enemy lines with a loud 'crack' as the noise rolled over the hills reminding us that "a war was going on!" Minute by minute went preciously by as the Blitz methods of modern war began to click.

The 2nd Squad, 3rd Platoon, had already connected the first two floats without mishap putting the two, sixty-five pound pins through the linking treadway while pulling another section laboriously into position. As we neared the center of the river, the current won its first battle. A float swept broadside in the current. The ropes snapped from men's hands and down the angry Isar it went. The power boat wheeled sharply about rapidly closing the gap to the float and move it safely to shore. Victory number two for the river came one hour later as we neared the far shore. When the power boat could no longer haul its load against the tireless current, a crane was run onto the bridge in hopes of pulling the sections to the head of the bridge where it could be connected. Suddenly, a float capsized from the pulling action of the crane. The heavy treadway hung vertically on its side and two men fell sprawling into the river. Frantically they swam ashore while the third man still clung to the upper side of the float. All three men were saved. Later, floats were punctured and the power boat fouled on a guy rope almost overturning it. Finally the far shore was reached and the last section pulled into place.

Waiting columns of vehicles began to warm their engines and the Armored Life-Blood of Victory began to flow. Another accomplishment by the engineers and the dangers of the enemy lobbing in mortars near the bridge did not deter these soldiers. There was a job to do and the job came first. Fortunately, the mortars were off target and in war, only the 'hits' count! Our artillery and air coverage spoke with authority, and shortly, silence was the only reply. Another 'battle' fell in favor of the cause for freedom.

Following the completion of the bridge, General Patton wrote a letter to our Battalion Commander, complimenting us on our fine achievement, with special recognition of the fine spirit and high morale that showed during construction of the bridge.

• 1st and 2nd platoons assembled the sections
• 3rd platoon connected the sections and secured guy-lines
• The three generals were:
  Brig. Gen. Smith - Armored Div. Commander
  Maj. Gen. Van Fleet - Corps Commander
  Lt. Gen. Patton - 3rd Army Commander
• Gesturing to our company Commander, Capt. Schwartz, General Patton said to General Smith, "You can thank his men for getting your ass across this river!"