Battle of the Rapido River

Background

By January 1944 the Allies had fought their way from Salerno to the Winter Line, and Lieutenant General Mark Clark's Fifth Army faced the Gustav Line: the German position behind the Garigliano, Gari and Rapido rivers, anchored on Monte Cassino. Behind it lay the Liri valley and Highway 6, the most direct route to the Anzio beachhead and Rome, and one of the few places in southern Italy where armour could be used. On 22 January VI Corps was to land at Anzio (Operation Shingle). To help it, Clark planned a three-corps attack on the Gustav Line that would pin the Germans in the south, draw in their reserves from around Rome and, if it broke through, let the 1st Armored Division drive up the Liri valley towards Frosinone and the beachhead.

The French Expeditionary Corps attacked in the mountains on 12 January. On 16 January II Corps found Monte Trocchio, the last height before the river, abandoned. British X Corps crossed the lower Garigliano on 17–18 January, and that success persuaded Kesselring to send his two reserve divisions south from Rome. On the night of 19–20 January, though, the British 46th Division failed to cross near Sant'Ambrogio, which left the American left flank open. The culminating blow was to be the 36th Division's crossing either side of Sant'Angelo on the night of 20 January.

History calls it the Rapido, but this stretch, below the point where a creek joins the Rapido south of Highway 6, is properly the Gari. The crossing was the American opening of what is usually counted as the first battle of Monte Cassino (17 January to about 11 February 1944). That battle went on with the 34th Division's attack north of the town from 24 January.

The armies

Major General Fred L. Walker's 36th Infantry Division had been a Texas National Guard formation. It had landed at Salerno, and in December the fighting at Monte Maggiore, Monte Lungo and San Pietro cost each of its regiments almost 1,000 men. Only about half of those losses had been replaced by January. The assault companies were under strength and full of new men who barely knew their leaders. Walker kept the 142nd Infantry in reserve and attacked with the 141st (Lieutenant Colonel Aaron Wyatt) north of Sant'Angelo and the 143rd (Colonel William Martin) south of it. Attached were two battalions of the 19th Engineer Combat Regiment and two companies of the 16th Armored Engineer Battalion, the 760th Tank and 636th Tank Destroyer Battalions, and chemical mortar companies for smoke. Sixteen battalions of artillery fired the preparation, and Combat Command B of the 1st Armored Division waited to exploit. The crossing equipment was poor: the plywood M2 assault boat weighed 410 pounds, pneumatic boats punctured easily, and with no standard footbridge to be had, the engineers improvised footbridges by laying Bailey catwalk on floats.

Opposite was Generalmajor Eberhard Rodt's 15th Panzer Grenadier Division, which Senger, commanding XIV Panzer Corps, rated his best. Its men held dugouts, concrete bunkers and portable steel pillboxes behind double-apron wire. A belt of mines a mile deep covered the American side of the river. Mortars, Nebelwerfers and hull-down tanks or self-propelled guns supported the line, and observers watched from Sant'Angelo's 40-foot bluff and from Monte Cassino.

The battle

The river here was 25 to 50 feet wide, 9 to 12 feet deep and swift, between near-vertical banks 3 to 6 feet high. No track to the crossing sites would bear a truck, so the boats were dumped near Monte Trocchio and the assault infantry carried them forward. German patrols were thought to be re-laying mines in the cleared lanes.

Night of 20–21 January, north of Sant'Angelo (CDB90 Rapido North I). Darkness brought thick fog. The 1st Battalion, 141st Infantry, found some boats at the dump already wrecked by shellfire. When the preparation opened at about 1930, German guns answered; Company B lost 30 men in one volley, its commander among them. Men scattering for cover strayed into minefields, the cord marking the lanes trampled into the mud. Wyatt had the preparation extended past H-hour (2000). By 2100 fewer than 100 men were across. Of four footbridges, a mine destroyed one, one was defective and shells knocked out two; a bridge patched from their remains went in at 0400, and by 0630 most of the battalion's rifle companies were over. With daylight coming, Brigadier General William Wilbur held back the 3rd Battalion. The men across dug in 200 yards beyond the river, cut off from all communication.

South of Sant'Angelo (Rapido South I). At the 143rd Infantry's northern site, 1,000 yards below the village, men of Company C crossed at 2000 against little opposition; then fire destroyed the boats and the first footbridge. Martin went to the river himself, routed engineers out of their foxholes, and by 0500 the 1st Battalion was over. By 0700 it was pinned in a pocket against the river. When German tanks joined in, Major David Frazior pulled out without waiting for Walker's order to hold; by 1000 the survivors were back. At the southern site, 500 yards further down, the 3rd Battalion's guides lost their way in the fog and led the boat parties into a minefield. Nobody crossed. The 15th Panzer Grenadier Division reported the assault detachments 'annihilated'.

21 January. At about 1000 Keyes, pressed by Clark to get armour across, ordered Walker to attack again at once. Walker set 1400, but the boats arrived late. He wrote that he expected 'a fizzle'. German reinforcements came up: the 211th Grenadier Regiment between Highway 6 and the Pioppeto creek, and the 3rd Battalion, 104th Panzer Grenadier Regiment, south of Sant'Angelo.

Rapido South II. At 1600, under heavy smoke, the 3rd Battalion, 143rd, ferried its rifle companies over in rubber boats by 1830; two companies of the 2nd Battalion followed after midnight. They got about 500 yards before grazing fire from wired-in machine guns stopped them. The 1st Battalion's Companies A and B crossed by 1835 but stalled 200 yards out; by 0500 Frazior and all three rifle company commanders were down. The Bailey bridges the tanks needed were never built: trucks bogged, and engineers stayed dug in a mile and a half away. Martin ordered a withdrawal, and by about 1240 on 22 January the regiment was back, apart from isolated groups.

Rapido North II. The 141st could not go until 2100. Footbridges went in at 0200, and by dawn the 2nd and 3rd Battalions were across. They found no survivors of the 1st Battalion. They pushed up to 1,000 yards and dug in. From 1300 the telephone lines failed; by 1600 the last footbridge had been hit, the boats were gone, and every company commander but one was dead or wounded. German counter-attacks at about 1600 and after 1700 struck the centre and both flanks. Between 1800 and 1900 about 40 men swam back; from about 2000 only German weapons could be heard. Keyes ordered the 142nd Infantry to try again, then let Walker cancel it.

Aftermath

When the 141st Infantry counted its men on 23 January, its three battalions mustered 398, 309 and 283. The division's own units had lost 1,681 men (143 killed, 663 wounded, 875 missing), not counting attached troops. Figures put before Congress in 1946 were higher, about 2,100 to 2,250. The 15th Panzer Grenadier Division claimed 500 prisoners and called its own losses negligible; a later American account puts them at 64 killed and 179 wounded. Senger grasped what Rodt's men had achieved only when his staff tallied the American dead and prisoners.

Clark wrote that 'some blood had to be spilled', and that he preferred it to be on the Rapido rather than at Anzio. Walker blamed 'the stupidity of the higher command'. Blumenson argues that the British Garigliano crossing had already drawn Kesselring's reserves south, something the Allied commanders could not have known. Kesselring later said the frontal attack should never have been made. VI Corps landed at Anzio on 22 January against little opposition, and Fifth Army shifted its effort north of Cassino.

In January 1946 the 36th Division Association, meeting at Brownwood, Texas, called for a congressional investigation of the 'Rapido River fiasco'. The House Military Affairs Committee met on 20 February and heard witnesses, Walker among them, on 18 March 1946. Secretary of War Robert Patterson had already found that Clark 'exercised sound judgment', and no investigation followed. The battle is still counted among the US Army's heaviest defeats of the war.

Wargaming it

The Rapido is a small battle with a brutal shape: two reinforced regiments trying to put six infantry battalions across a 50-foot river at night and in fog, through a mile-deep minefield, against a dug-in panzer grenadier division that needs few men to hold its line. It suits company-level rules with platoon or section stands, turns of half an hour to an hour, and a table covering about two miles of river either side of Sant'Angelo, from the S-bend in the north to the Liri–Gari junction.

The best mechanics are logistical. Boats and footbridges are carried from the Monte Trocchio dumps and lost to fire and mines on the way; guides wander off the marked lanes; a bridge may last an hour. Communications across the river should be fragile, German observation from the bluff and the abbey should govern daylight movement, and smoke should blind the attacker's own artillery.

The American player must decide whether to commit the reserve battalion on the first night or pull back before dawn, whether to attack again in daylight under smoke, as Keyes ordered, or wait for night, as Walker wanted, and whether to throw in the 142nd. The what-ifs are operational: a successful 46th Division crossing covering the left flank, Keyes's idea of going in through the British Garigliano bridgehead, or Walker's preferred envelopment over the mountains to the north. Played straight, the Americans lose; victory conditions might reward holding a bridgehead at dawn on 22 January.

Maps and pictures