Crossing the Rhine.

Discussion in 'Home' started by Trux, Sep 13, 2018.

  1. Trux

    Trux 21 AG

    DD Tank Operation.

    For the Rhine Crossing it was not intended that the DD tanks should be used in an assault role but that they should be used in order to have armour support for the infantry sooner than would be possible using ferries. The infantry would make an assault crossing in the hours of darkness in the early morning while the tanks waited until daylight.

    Once ashore DD tanks were to be used in the same way as a normal tank regiment. It was considered important that they should be used in a concentrated fashion rather than be spread across the whole front and that being specialist equipment and in limited supply they should be withdrawn as soon as possible and replaced by a standard armoured regiment.

    A major problem for DD tank operations, and one that affected all aspects of the plan for river crossing was finding suitable exit points on the far bank. Failing this then exit points should be improved before DD tanks can cross.

    79 Armoured Division set up G Training and Experimental Wing to solve the problems of exiting a river. Platypus grousers were used to reduce ground pressure but were of limited value. The longer British version spread the weight and reduced ground pressure but was easily damaged. The shorter US version was more secure but less effective. Carpet laying devices on AVRE had been used on D Day and the idea was developed and adapted to the Buffalo. A set of rails was mounted on the Buffalo and a carpet of chespalings linked with cables was placed on top. As the Buffalo emerged from the water it lowered the end of the carpet which went under the tracks. This pulled the rest of the carpet down and rapidly laid a 75 foot length. Sherman DD tanks could mount the banks using this carpet to give grip.

    Finding suitable points for DD tanks to enter the river was less of a problem since if the tank lost grip it would slide into the water where it should be anyway. Obviously the entry point should be chosen to make entry as safe and easy as possible but the most important factor was finding a site which would allow the tanks to cross to the exit point with a minimum of effort and risk. This raised the problem of navigation on a wide river. Tanks would have to make allowance for the current and be able to identify the exit point.

    J Wing was established to study the problem of navigation. Three methods were developed. The first was a radio direction keeping equipment which used two Wireless sets No 19 to give a beam which DD tanks could use as a guide. The traditional magnetic compass was used together with gyro compasses. Tabby infra red headlights and infra red beacons were developed but not much used as DD tanks crossed in daylight. It was decided that since the DD tanks could not effectively use their armament in the dark they should not cross the river until dawn.

    Of course when you solve one problem you often create others. If there is only one exit then there are two risks. One is that a tank will become bogged down or otherwise block the exit. This was solved by providing multiple tracks at each exit so that only one tank in each wave would use each track. Second is that if the current carries a tank past the exit it will not be able to get out of the river unless there is an alternative exit point provided further down stream.

    The DD regiments employed in the Rhine Crossing were normal armoured regiments which received some special equipment and training.

    Regimental headquarters had three Sherman DD tanks instead of normal tanks.

    Headquarters Squadron had the following special equipment:
    - The Reconnaissance troop. This troop was to cross the river ahead of the main body and select good landing places for the DD tanks. There was a headquarters section with LVT II and three sections, one per squadron. Each section had two LVT II with carpet laying equipment and one LVT IV carrying an airborne bulldozer to improve the chosen landing places.
    - The Intercommunication troop. This troop was issued with nine M29 truck 10cwt tracked (M29 Weasel). Although these Weasels seem to have been the amphibious M29C version they were carried across the river in LVT IV since the width and flow of the river were thought beyond their capabilities. They were particularly used on the river banks and flood plain where their low ground pressure gave them good mobility.
    - Administrative troop had two 3ton 4 X 4 DD compressor to recharge air cylinders for inflating the flotation screens. Small compressors were also available for use in inflating the screens.

    Each of the three squadrons had the following special equipment:
    - Squadron Headquarters. This had three Sherman DD instead of normal Sherman and twelve DUKW instead of 3 ton 4 X 4 GS. These carried mainly fuel and ammunition.
    - Each troop had four Sherman DD tanks.

    The DD tank used in the Rhine Crossing was a Sherman MkIII (M4A2) with diesel engine. It was modified for flotation by fitting a canvas screen which was erected using canvas tubes inflated by compressed air. As the screen rose it lifted a tubular metal frame that maintained the shape of the screen. The frame was supported by metal struts which were locked into position manually when the screen was fully inflated. The canvas flotation screen was divided into three parts. The lower part was three layers thick to give strength where it was most needed. A second part had two layers and the highest part had only one. Experience had shown that when DD tanks climbed ashore there was a danger that water would lap over the rear of the screen so an extra raised screen was added at the stern. Once ashore the screen could be very quickly lowered hydraulically and the tank was ready for action without further work being necessary.

    Propulsion when afloat was by two propellers. These were driven by an ingenious, if complicated, drive system. The Sherman tanks tracks were driven by drive sprockets at the front. The DD Sherman had drive sprockets fitted to the rear idler wheels and these were driven by the tracks. The propellers were raised and lowered hydraulically. When raised they were not driven but when lowered they engaged with the sprockets on the rear idler and provided propulsion on water. The tracks remained driven so that there was no break in transmission when the tank entered or exited the water.

    Steering when afloat was by swivelling the propellers. Steering presented problems since the driver’s position was under water when the tank was afloat. The driver was provided with a periscope but this gave limited vision. There was a second steering position behind the turret. The tank commander could stand on a platform and use a tiller to steer the tank. The driver had a gyro compass to enable him to maintain a course and the commander had a magnetic compass.

    The Assembly Area.
    Tanks should be carried on transporters to the Assembly Area. This should be some three miles from the river and have good natural camouflage. There should be suitable routes forward to the crossing site. The tanks should arrive at least 48 hours before the planned crossing date to allow a full maintenance service to be carried out. Final adjustments will be made and any damage suffered en route repaired. Crews will be briefed and rested and liaison with the infantry carried out.

    The Inflation Area.
    For a river crossing the DD regiment needed a well planned and reconnoitred approach. The squadrons were called forward from the Marshalling Area to an Inflation Area with the canvas flotation screens lowered to avoid detection and to avoid damage to the canvas. The route must be carefully checked and improvements made if necessary.

    The Inflation Area is a forward area in which the DD tanks can halt and inflate their flotation screens and from which access is available across open country to the river. Passage through woods, hedges, bushes etc ruins the equipment once it has been inflated. The Inflation Area should also be sheltered from view so that the DD tanks can inflate the screen without attracting attention. A route to the river would be marked out and a site found where the tanks could enter the water at a suitable angle.

    The DD tanks will need to travel as near to the crossing site as possible before inflating the flotation screens. The screens are very liable to suffer damage from any trees or other obstacles so the route must be checked and if necessary improved. Good signing and traffic control will be needed to avoid conflict and delays. The route will probably cut across routes earmarked for other users.

    The inflation area should be some 1000 yards from the river and away from troops, vehicle concentrations and other likely targets for enemy artillery. It should be large enough for tanks to be dispersed and there must be a direct and easy route to the launching sites.

    In the inflation area the flotation screens should be erected and propellers tested. Unit fitter and LAD detachments, including fabric refitters accompany the tanks to the inflation area to make sure that all is in good order. DD units have a Ford WOT6 compressed air lorry which ensures a supply of compressed air cylinders for erecting the screens. An ARV should accompany each squadron to ensure that routes are not blocked by casualties.

    The route from the Inflating Area to the river was more than a mile long and cut across routes designated for an LVT ferry so careful timing and control was required. The crossing was timed for 0545 to allow it to have cleared the river and bank area before the follow up storm boat ferry operation started at 0600. Reconnaissance sections of the regiment had crossed earlier to find and improve landing places for DD tanks.

    Far Bank Reconnaissance.
    Each DD regiment provides two reconnaissance parties, each carried across the river in a LVT.

    LVT No1 carries:
    DD Officer.
    LVT NCO.
    3 LVT crew.
    3 DD other ranks.
    2 RE other ranks.

    LVT No 2 carries:
    LVT Officer.
    3 LVT crew.
    DD NCO.
    2 DD other ranks.
    2 RE other ranks. Airborne dozer and mate.

    Each LVT carries the following stores:
    4 Lane marking lamps.
    4 Lane marking posts.
    5 red and yellow flags with posts.
    15 green and white flags with posts.
    Floodlight and stand.
    Signalling lamp.
    10 long angle iron pickets. To fasten down carpet.
    10 short angle iron pickets. To fasten down carpet.
    2 sledge hammers.
    2 Shovels.
    15 yards of chespale carpet. Reserve for repairs.
    Airborne bulldozer.
    Large lane marker for use by day.
    Tow rope.

    The DD officer commands the reconnaissance and carpet laying party and always takes the upstream lane in LVT No 1. He will lead the two reconnaissance LVTs to the far bank. On landing he reconnoitres two landing lanes accompanied by the LVT officer and NCO and his own NCOs. He selects lanes, marks them with flags and allots tasks to the bulldozer. When the lanes are sited he calls over the LVT carpet layers by radio. He reports to his regiment by radio when lanes are completed and ensures that DD guides are posted on the lanes. He keeps the lanes repaired until the completion of the DD landings and controls one remaining LVT for radio communication and recovery. One DD other rank acts as runner.

    DD NCOs are posted one on each lane. They are responsible for marking out the lanes as ordered by the DD officer. He ensures that the homing signals for the carpet laying LVTs are in place, reports progress and guides DD tanks into lane. Two DD other ranks assist the NCO in marking the lane, picketing the carpet and maintaining it. One will be detailed to operate the landing signal when required.

    The LVT officer goes with LVT No 2. He accompanies the DD officer on his reconnaissance and makes sure of the DD officers requirements regarding carpet positions. He guides the carpet layers and reports to the DD officer when both lanes are complete. After the carpet layers have laid carpets he unloads his own 15 yards of carpet and leads the carpet layers back to the DD inflation area. When released from the DD regiment he leads his troop to the LVT collecting area.

    The LVT NCO supervises the laying of the carpet on his lane and reports completion to the LVT officer. He remains on the far bank with his LVT to assist the DD officer in radio communication and recovery. The LVT crews operate communications between the reconnaissance party and DD regiment. They assist in unloading and carrying stores. They lay the reserve 15 yards of carpet if required.

    In case the above is insufficiently clear the instructions lay down the following sequence of events.

    The DD reconnaissance party marks the approach from the Inflation Area to the launching site.
    Two reconnaissance LVTs launch, No 1 leading, and land in the centre of the area.
    DD officer and two DD NCOs and LVT officer and two NCOs dismount and carry out a reconnaissance of the landing area.
    Stores and equipment are unloaded at the lanes when they are sited.
    DD NCOs and assistants mark lanes.
    When lanes are sited the DD officer calls forward carpet laying LVTs by radio.
    A signal operator on each lane starts sending a homing signal. Each lane has its own signal.
    Signal operator switches on floodlight for bulldozer work and carpet laying if required.
    LVT officer and NCO direct carpet laying on their respective lanes.
    LVT officer informs DD officer when carpet laying is complete.
    DD officer reports that lanes are complete to DD regiment.
    LVT No 1 and LVT officer remain near the lane until DD landing is complete, assisting with radio communication and recovery.
    When released LVT officer brings back DD reconnaissance party to the Inflation Area.
    LVT officer leads his troop to the LVT Collecting Area.

    The Navigational Aids.
    Before moving to the Forming Up Place gyros will have been checked by the drift chart. If circumstances permit the compass will be swung.

    In the Forming Up Place the gyro will be switched on and cage on the bearing given by the squadron or troop commanders. The quickest and simplest way to cross a river is to steer at right angles to the current. A simple calculation can then be made to determine the point at which the craft will beach. It is necessary to know the speed of the current, the speed of the craft and the width of the river.

    When moving from the Forming Up Place to the Launching Point the prismatic compass will be set. By night the route will be marked by lights and on a stretch at least 100 yards long the route will be marked on both sides. This part will be absolutely straight and the gyro compass can be set by it.

    During the crossing the driver will steer on the given gyro course. The commander will check by using the prismatic compass and correct the course if necessary.

    DD tanks will enter the water at right angles to the bank and follow the gyro course until just before reaching the far bank when he will turn slightly in the direction of the current. Since the current will tend to swing the stern round when the bow is on shore this slight turn should allow the DD tank to climb the bank at the correct angle.

    In the above it has been assumed that while the crossing will be made in daylight the movement on the near bank will take place in darkness.

    A word of caution.
    The above is based on tactics and organisation recommended by 79 Armoured Division. It cannot be guaranteed that it applies to the Rhine Crossing in every particular, although it was based on that operation.

    Plunder DD.jpg

    Last edited: Jul 21, 2021
    Aixman, stolpi, ted angus and 3 others like this.
  2. Trux

    Trux 21 AG

    Stormboat Operations.
    The stormboat was intended for use on wide and fast flowing rivers. The previously used assault boats were canvas and propelled by men with oars, or paddles. It was not practicable to cross a river like the Rhine in such a craft in an assault role although it could be used as a ferry with a cable to prevent drifting downstream, and perhaps a winch. This was hardly suitable for an assault role.

    The stormboat was a powered wooden boat 20 feet long and 6 foot 6 inches wide. They were designed to nest inside one another for transport.

    The boat had an oak frame with sides and bottom clad in plywood. There were seats running down each side and these could be used as tracks for 6pdr anti tank guns and jeeps. The flooring between the seats was hinged to allow for bailing out water.

    The boat was powered by a 55 horse power outboard motor. The stern was cut away to provide a mounting for the motor and this allowed the motor to be tilted so that the propeller was clear of the river bottom.

    Stormboats were carried in 3 ton lorries. Three boats could be nested together with the three motors inside the top boat. They were loaded with the stern to the front of the lorry. Ramps were also carried to allow anti tank guns and jeeps to be loaded and unloaded.

    The boat weighed 800 pounds without motor or ramps. The motor weighed 180 pounds and the ramps 250 pounds. The boat had a crew of two men and could carry eighteen fully equipped infantrymen. Fully loaded the speed was 10 miles an hour but 20mies an hour could be reached if empty.

    15 Division did not use stormboats in the assault role but as ferries for follow up and reserve personnel.

    Stormboats were heavy and were therefore moved into camouflaged hides which were near enough to the river for them to be manhandled. Each boat required fourteen men to carry it and each outboard motor required a further three. Carrying parties came from pioneers of the Bank Group. The hides were close to the Stormboat Waiting Area where personnel waited to be called forward to board for the crossing. An Infantry Track linked the Marshalling Area to the Waiting Area. This was a marked path which kept personnel separated from vehicle traffic.

    Ideally stormboats should be launched in sheltered water out of sight of the enemy. The launching parties are vulnerable in the final approach and launching. Care must also be taken to start the outboard motors only when they are in more than three feet of water otherwise they may be damaged. Once launched and manned by the Royal Engineer crew the stormboats should be taken to the waiting infantry. The boats should be manoeuvred so that the bows are against the river bank and the motor in deeper water. Infantry may then board over the square bows, using ramps if necessary.

    Moving stormboats to the hides is an engineer responsibility, as is the operation of the ferry itself. All movement is under the control of the Bank Unit. They will carry the boats to the water, call troops forward, supervise loading and unloading and direct infantry to their assembly area.

    It is not practical to operate more than twenty four stormboats at one ferry point. This is a sufficient number to rapidly transport all the required infantry personnel. The number is maintained by providing a reserve of a further twenty four boats. Vehicles cross separately and rejoin the personnel in the Assembly Area on the far bank.

    Extra stormboats or other craft may be provided for rescue and recovery tasks. The loss of boats due to enemy shelling remains a danger for some time. A greater danger is that of the outboard motor failing and allowing the craft to drift. This not only endangers the crew and passengers but is a threat to any ferry or bridging operations downstream.


    Aixman, ted angus and alberk like this.
  3. Trux

    Trux 21 AG

    Now the plans have been made, orders issued, men and equipment moved forward, the weather is good and the river levels normal so if you are ready lets go and cross that river.


    The first objective in an assault river crossing has to be the securing of a deep enough lodgement to prevent an enemy firing on the crossing sites with small arms. In the case of the Rhine crossing this meant clearing and holding the bund, the manmade flood defence which was some distance from the river and some five metres high. If the enemy held this, or any part of it he could dominate the crossing sites, the river bank and the area between the river and the bund. If friendly forces held the bund then the enemy could not see the crossing places or fire on them with small arms. Artillery would remain a problem.

    The second objective was to clear the far bank to a point where the enemy could no longer observe the river crossings and be in a position to direct artillery fire. Unobserved artillery fire would still be possible but this was never nearly as effective as observed fire. This second objective meant clearing the higher land which was further away from the river. In 15 Divisions area this would be partly done by the airborne forces

    The third objective was to clear a bridgehead deep enough to prevent all enemy artillery fire reaching the crossing places.

    Despite the seemingly overwhelming concentration of artillery, the special assault equipment, the over establishment infantry, air support, airborne forces and meticulous planning it should not be thought that the assault was to easy. Opposition and losses varied widely but there was much tough fighting before the assault units could consider the far bank secure.

    When 15 Division launched its assault 1 Commando Brigade had already landed upstream and secured the right lank while 51 Division had landed downstream and secured the left flank.

    With troops established on both flanks the assault on the centre was launched by 15 Division at 0200 hours. 44 Brigade and 227 Brigade each deployed two battalions, each with assault troops in Buffaloes and a follow up in stormboats. Soon 46 Brigade was ferried across also.

    The Rhine was considered too wide and too fast flowing to allow the use of assault boats manned by infantry. Buffaloes were used for the assault waves. Stormboats manned by engineers and powered by outboard motors were used instead. Buffaloes also replaced the lighter rafts since they could carry light weapons, 6pdr anti tank guns, jeeps, 3.7” howitzers and carriers. Some were converted to carry 17pdr anti tank guns. Stormboats could also carry jeeps and 6pdr anti tank guns.

    Once the assault force and close support weapons were across the river Buffaloes and stormboats ran a ferry service while the raft ferries were constructed. The raft ferries continued in operation until the bridges were completed.

    In the following posts the actions of the following will be described.
    44 Brigade.
    227 Brigade.
    4 Armoured Brigade.

  4. 51highland

    51highland Very Senior Member

    From 5th Camerons regimental History; rhineCrossing.jpg
    Trux likes this.

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