Engineer’s Report of the Roer River crossing at Linnich, Germany
Scope : A report of the planning, preparation, and crossing phases in which the 171st Engineer Combat Bn, XIII Corps, was involved while in direct support of the 84th Infantry Division in its assault crossing of the Roer River at Linnich, Germany. Period covered : Dec 2 1944 to Feb 24 1945; Lt Col Charles R. Keasy
171st Engineer Combat Battalion, Commanding
The Roer River rose to historical prominence in the winter of 1944/1945 when it became an integral part of the German western border defenses. It effectively closed the 25 mile gap in the Siegfried Line which the American advance through Aachen had made. For the 9A a further invasion of Germany to reach the Rhine depended upon the forcing of the Roer River. (Lt Gen W. H. Simson, Rehearsal for the Rhine, Military Review, October 1945)
Roughly, the Roer River runs parallel to the German frontier from Roermond in the north, where it joins the Meuse River to Düren in the south. It also parallels the Rhine River about 25 miles further east and is an effective barrier to any attack from the west aimed at the Ruhr Industrial Area. The advance to the river had been a slow fight against determined resistance and the enemy was quick to respond to any probing of the east bank. The situation called for the build-up of a powerful attacking force before a crossing could be forced. Detailed plans for the Roer crossing were formulated early in December after elements of the XIX Corps and the XIII Corps in the 9A zone reached the river at Jülich and Linnich. However, the operation was delayed for more than a month by the German Counter Offensive in the Belgian Ardenne. A further delay was caused when the enemy blew the gate valves of the Schwammenauel Dam south of Düren as they retreated before the 1A toke the Dam. As a result, the Roer River north of Düren rose to a flood height of 10 to 12 feet and to a width of 200 to 260 feet in the channelized portions and 100 to 300 feet where the river overflowed its banks. The current in the channelized portions of the river also increased in swiftness from 5 to 9 feet per second. Heavy thaws which started late in January added to the flood conditions which remained throughout most of February. As a result of these delays the planning, preparation and training phases of the crossing were continued. As the river itself now became the main obstacle to the crossing an engineer combat group was assigned to support each assault division. Each engineer combat group was to consist of three engineer combat battalions and supporting engineer bridge companies. River crossing schools were set up along the Meuse River and Infantry – Engineer teams rehearsed assault crossing while supporting engineers increased their technical proficiency in bridge construction in swift water. On the 9A front the XIX Corps was to cross on the right with its main effort at Jülich, the XIII Corps in the center with its main effort at Linnich, and the XVI Corps on the left to cross at Hilforth and Linnich after the XIII Corps had created a bridgehead for it. The 2-BA was to the left of the 9A and the 1A was to the right of it.
The XIII Corps planned to cross with two infantry divisions abreast, the 84-ID on the left and 102-ID on the right with the 5-AD in reserve. Both divisions were to make their main effort at Linnich as the river above and below the town had flooded the lowlands to some 1500 to 3000 feet in width while in the channelized section in and near Linnich the width varied from 200 to 250 feet. The 84-ID planned to cross on a one-battalion front in two waves of two companies each. Local conditions along the river dictated such a plan. The divisional engineers, the 309-ECB, were assigned the responsibility of the assault boat crossing. The 1149-ECG was placed in general support of the 84-ID and the 171-ECB was placed in direct support of the division with responsibility for the assault bridges. Plans, as finally developed in conferences between the 84-ID, the 1149-ECG, the 171-ECB and the XIII Corps Engineer, called for six bridges to be constructed in the division zone. Three infantry footbridges were to be placed in operation, construction to be started as soon as the infantry assault wave reached the far shore and the bridges completed by H+45 (minutes) in time for the second battalion of infantry to cross. A Infantry Support Bridge and an M-2 Treadway Bridge was to be started as soon as small arms and automatic weapons fire was eliminated from the sites. The estimated completion time was H+5 (hours) for the Infantry Support Bridge and H+7.5 (hours) for the M-2 Treadway Bridge provided the sites were clear at H+1 (hour). The second M-2 Treadway Bridge was to be constructed on a site approximately 2000 yards down-stream after the infantry had cleared the bridgehead. The bridging equipment for the crossing included 100 M-2 Assault Boats, 432 feet of footbridge, 400 feet of infantry support bridge, 532 feet of M-2 Treadway bridge and 6 LVT’s.
Note on Assault Boats – US – M-1 and M-2
Assault Boat M-1 : The assault boat M-1 has been superseded by the assault boat M-2.
(a). The M-1 boat is a skiff type, flat-bottomed plywood boat. It is 13 feet 6 inches long, weighs about 200 pounds, and has a useful displacement of 3,200 pounds. It can carry safely, in addition to a two-man engineer crew, any one of the following loads of combat-equipped infantrymen and weapons :
1 : 9 riflemen with individual equipment
2 : 8 men, 1 Cal .30 light machine gun, and 20 boxes of ammunition
3 : 8 men, 1 Cal .30 heavy machine gun, and 13 boxes of ammunition
4 : 8 men, 1 Cal .50 machine gun, and 4 boxes of ammunition
5 : 7 men, 1 81-MM mortar, and 50 rounds of ammunition
6 : 9 men, 1 60-MM mortar, and 150 rounds of ammunition
7 : 7 men and equipment of an infantry communication platoon wire section
(b). The M-1 boat is not equipped with hinge connections for making assault-boat pontons.
Assault Boat M-2 (1909) : The Assault boat M-2 (photos bellow) is a scow type plywood boat with square stern, flat bottom, and slightly tapered bow. It has 13 feet and 7 inches long, weighs about 410 pounds, and has a useful displacement of 4,000 pounds. Each M2 boat is equipped with two hinge connections and one boat-connecting pin, so that two boats may be coupled together, stern-to-stern, to form an assault-boat ponton of the type used in the infantry support raft and in the expedient assault-boat bridge. Two spacers for plywood treadways are located in each gunwale of the boats. Nine paddles are provided with each boat.
(a). A three-man engineer crew is needed to operate an assault boat M-2. The boat safely carries the following loads of combat-equipped infantrymen and weapons in addition to the three-man engineer crew :
1 : 1 rifle squad (12 men) with individual weapons and combat equipment
2 : 2 light machine-gun squads (10 men), 2 Cal 30 light machine guns, 20 boxes of ammunition
3 : 1 heavy machine-gun squad (7 men), 1 Cal .30 heavy machine gun, 13 boxes of ammunition
4 : 1 Browning machine-gun squad (7 men) with caliber .50 machine gun and 4 boxes of ammunition
5 : 2 60-MM mortar squads (10 men) with two 60-MM mortars and 72 rounds of ammunition
6 : 1 81-MM mortar squad (7 men) with 81-MM mortar and 50 rounds of ammunition
7 : 1 infantry communication platoon wire section (8 men) with complete equipment
2 assault boats lashed together can carry the 37-MM antitank gun, its squad of 5 men, at least 100 rounds of ammunition, and an engineer crew of 3 men. Carrying : 10 to 12 men carry the boat. It is carried inverted to within a few yards of the water’s edge; then it is turned over, carried upright to the water’s edge, and launched. Paddling : The engineer in charge of the boat kneels at the stern and steers. The other two engineer crew members kneel, one at each side of the bow, and paddle. Six passengers also paddle. Transportation : The boats are nested in groups of seven (maximum 10) for transportation. These may be carried on 2½-ton trucks or two-wheel trailers.
After final approval of these plans the 74th Light Ponton Company and the 989th Treadway Bridge Company was assigned to the 171-ECB by the 1149-ECG for the operation. Intensive training and preparations were immediately started so that the line companies of the 171-ECB and the attached units could perfect the details of the actual crossing. A Co volunteered for and was given the task of constructing the three Infantry Footbridges and the Infantry Support Bridge. B Co was assigned the task of constructing the M-2 Treadway Bridge at Linnich. C Co was responsible for constructing the M-2 Treadway Bridge at the Korrenzig site down stream from Linnich. One platoon of A Co (171-ECB) was assigned the task of constructing approximately 100 yards of plank tread-approach road for the Infantry Support Bridge. Reconnaissance of the river line during this period was continuous. The Battalion Commander, S-3 and Company Commanders of the line companies and attached companies spent hours daily studying aerial photographs, the river, the current, eddies, near and far shore and approaches, and the enemy. Scale sketches were made of the area with detailed sketches of the proposed crossing sites. Final plans and orders were prepared, equipment inspected, training perfected, and reserve equipment secured and stock-piled. Only the flood condition of the river delayed the crossing.
On Feb 21, the Army Engineer advised that, though the river would be still swollen, we would be able to negotiate it on Feb 23. Acting on this prospectus, I, (Lt Gen William H. Simpson, CG 9A) issued orders for the attack on the morning of Feb 23, proceeded by a 45 minutes artillery barrage. (Lt Gen William H. Simpson, Rehearsal for the Rhine, Military Review, Oct 1945)
Lt Gen William Hood Simpson (May 18 1888 – Aug 15 1980) was a distinguished US Army officer who commanded the US Ninth Army in northern Europe, during World War II, among other roles. William Simpson was born May 18 1888 at Weatherford, Texas. After graduating from the United States Military Academy in 1909, he was commissioned into the infantry. Before US involvement in World War I, Simpson served in the US and in the Philippines, including the Mexican Punitive Expedition, in 1916. He was promoted to Captain in May 1917 and served with the 33rd Division throughout World War I, receiving temporary promotions to Major and Lieutenant Colonel and becoming divisional Chief-of-Staff.
In the inter-war years, 1919–1941, Simpson filled staff appointments and attended military schools, both as student and as instructor. From 1932 to 1936, he served as the Professor of Military Science at Pomona College in Claremont, California. In mid-1940, he was appointed to command the 9-ID at Fort Sam Houston, Texas. Before US entry into World War II, he had commanded divisions and received promotion to temporary Major-General, taking 35th Division from Camp Robinson, Arkansas, to a training site in California.
Further promotions followed and in May, 1944, as a Lieutenant General, Simpson took his staff to Britain to organise the 9A. This formation was activated as part of Omar Bradley’s 12-AG, on Sep 5 at Brest, France. The 9A joined the general advance and, after a month in the Ardennes the 9A was moved further north. In November, 1944 it broke through the Siegfried Line and advanced, in some of the heaviest fighting of the war, the Roer River sector. At this point the advance stalled, due to the threat posed by dams upstream. After the Battle of the Bulge, the 9A remained with FM Montgomery’s 21AG for the final attack into Germany. As part of Operation Plunder, the Rhine was crossed on Mar 24, 1945, north of the Ruhr industrial area and on Apr 19 the 9A made contact with Courtney Hodges’ 1A, making complete encirclement of the Ruhr. On Apr 4, it had reverted to Bradley’s 12AG. The Ninth was the first American Army across the Elbe, on Apr 12.
In a sense, the operation,to be known as Operation Grenade, started with feints on the two nights before the actual crossing. On the night February 20 to February 21 1945, an artillery concentration was fired from 0200 to 0205 a.m. and a two-hour smoke screen was maintained along the far shore. On the following night 21 to 22, the concentration was repeated but the time was changed to 0500 and the place was changed to farther upstream. The following smoke screen was maintained most of the night to allow the engineers to work near the river bank. One night later, 22 to 23, under cover of the smoke screen, the 309th Engineer Combat Battalion were able to move the assault-boats to covered positions within 1000 yards of the river and the 171-ECB were able to place the footbridge equipment in covered positions within 1500 yards of the crossing sites. Later that night, under cover of the smoke screen the 309-ECB cleared the routes to the river and marked them with tracing tape. Six lanes were laid out from the final assembly area to the boat group area and 35 lane were laid out from the boat group ares to the water’s edge.
It was D-Day, Feb 23 at 1000 the 309-ECB began to carry the assault boats to the boat assembly areas. The 171-ECB carried the foot bridge to positions directly in front of the bridge sites and carried the plank for the plank tread approach road to the proper sites. By 0230 everything was in position and at 0245, Division Artillery, Corps Artillery, Army Artillery and all supporting weapons opened up with their 45 minutes preparation. At exactly 0330, the artillery barrage was shifted back a few hundred yards. The engineers rushed forward to the footbridge sites with their equipment. The first wave of 35 boats, carrying A and C Cos 1/334-IR, hit the water. These two companies crossed on a front of approximately 700 yards. The boat trip took about ten minutes. The second wave of boats, bearing C and D Cos, hit the water at 0345. By 0405, the entire 1st Battalion was safely across. The casualties were negligible.
(Lt Theodore Draper : The 84-ID in the Battle of Germany, 1946)
At the footbridge sites elements of A Co, 171-ECB had crossed in assault boats with the first wave of infantry and had attached the anchor cables and float cables to ample hold fasts. All three bridges were partially constructed before the enemy reacted to the attack with heavy-mortar and artillery fire. Construction continued in spite of numerous casualties. Footbridge No. 1, on the right-was almost completed when enemy automatic weapons’ fire broke out from a stretch of shore that had not been cleared by the infantry, causing severe casualties and forcing the engineers from the site. Footbridge No. 2 was completed by 0410 but it was immediately knocked out by assault boats that drifted downstream from another crossing site. Footbridge No. 3 was completed at approximately the same time but it was knocked out by a direct hit from enemy artillery before the infantry could use it.
Spare equipment and equipment salvaged from other bridges was brought up to the site of Footbridge N°2, and 1 instead of 3 footbridges was placed in operation. However, this footbridge was not completed in time for the second crossing battalion, 3/334-IR to use. (Lt Theodore Draper, The 84-ID in the Battle of Germany, 1946)
The 3rd crossing battalion, 2/334-IR was therefore, the first to use the footbridge when it crossed at 1130. The same enemy automatic weapons fire that caused abandonment of footbridge No. 1, also caused considerable delay in starting construction of the infantry support bridge. Engineers from A Co, 171-ECB suffered a number of casualties on the site before elements of the 3/334-IR had cleared out the enemy pocket that had been bypassed by the 1st Battalion. However, by 0900, A Co, less the platoon that was still working on the footbridge at site No. 2, restarted work on the infantry support bridge, and, with the assistance of the platoon of C Co who had completed the plank-tread approach road to the site, completed the bridge and had traffic rolling over it 1700 despite damage done to the bridge during construction by increasingly heavy mortar, rocket, and artillery fire. Enemy resistance from a demolished factory and a partially demolished concrete pillbox directly opposite the Treadway Bridge site kept B Co off the site until noon when an assault team from the 2/334-IR, effectively cleaned out the enemy pocket. Construction started at once and at 1900, just as the bridge was being completed, enemy jet planes (ME-262) came over, dropped flares, circled and made a bombing run on the bridge and then circled back on a strafing attack causing extensive damage to both the Treadway Bridge and the Infantry Support Bridge. As a result of this enemy action, no tanks or tank destroyers were able to cross the river DDay leaving the infantry completely without armor support. However, during the 2 hours period that the Infantry Support Bridge had been opened, ammunition trains and some towed 57-MM AT guns had crossed to the infantry.
The tactical situation was such that C Co, with its Treadway equipment, had to be called from the Korrensig bridge site and its equipment used to replace the Treadway Bridge that had just been destroyed. C Co was assigned the task of replacing the Treadway Bridge, B Co took over the task of repairing the Infantry Support Bridge, and A Co who had suffered heavy casualties, the task to reorganize. At 0500, DDay + 1 24 enemy aircraft and artillery again damaged the Treadway Bridge and destroyed the Infantry Support Bridge. C Co repaired the Treadway Bridge, A and B Cos combined with what effective they had left, rebuild the Infantry Support Bridge. By 1130 the Treadway Bridge was repaired and the first tanks from A/771-TB crossed the Roer River. By 1400, the Infantry Support Bridge was again opened to traffic. After 42 hours of constant effort on the part of the Engineers, the bridges were in and in to stay, the infantry was getting the reinforcement it needed and had the bridgehead well under control. AAA units kept the enemy air away from the bridges and the infantry had driven the enemy beyond the range of his light and medium artillery.
Don’t Forget to Remember