Royal Army College

Lesson Overview

This is the humanitarian heart of the course. Everything you have learned so far, the safe handling of tools, the knots and lashings, the building of cover, the moving of water, comes together here in the work the Royal Kaharagian Army is most likely actually to do: holding back a flood, making safe a building a storm has broken, and clearing the debris that traps and endangers people. A small, lightly armed home-defence force will spend far more of its service raising a sandbag bank than fortifying a position, and the soldier who can do this work well, and safely, is worth a great deal to a stricken population.

The work is help, not force, and it is done under a plain constitutional rule that governs the whole of it: the Army aids the civil power and never supplants it. The civil authorities and the emergency services lead the response and hold responsibility for the people; the pioneer comes on their lawful request, takes a defined task under their direction, and hands it back when they can manage again. This is the rule of the Aid to the Civil Power course (HCR 210), and a disaster does not suspend it but sharpens it, because a disaster is exactly the moment a disciplined body might be tempted to take charge, and exactly the moment it must not. Above the constitutional rule stands a safety rule that runs through every section below: make safe first, and do not become a second casualty.

By the end you will be able to explain the pioneer's part in a disaster and the rule that the Army aids and never supplants the civil power; build a sandbag wall the right way, raise expedient flood barriers, protect a doorway or a key point, and channel and pump water away, while knowing the limits of what a sandbag wall can hold; shore and prop a damaged structure to make it safe enough to work near, with a sober respect for the danger of a partial collapse; clear debris safely, assessing before moving anything and watching for loads that hold others and for buried services; and apply the overriding rule of all disaster work, to make safe first, assess the scene, work in pairs, take qualified judgement on any structure, and hand serious rescue to the specialists whose work it is.

Key Terms

Aid to the civil power: the principle, governing this whole lesson, that the Army acts only on the lawful request of the civil authority, under its direction, for a defined task, and never takes over the response (HCR 210).
Sandbag wall: an expedient barrier of filled bags laid in bonded courses to hold back water or stop debris; effective only when filled, placed, and bonded correctly, and limited in the head of water it can hold.
Bonding: the laying of each course of bags so the joints are staggered over the bags below, as in brickwork, so the wall acts as one mass and not as loose stacks that slide apart.
Expedient barrier: a flood defence improvised from what is to hand, plastic sheet weighted at the foot, earth-filled containers, a board-and-bag dam across a doorway, when proper materials or time are short.
Shoring: the temporary propping of a weakened wall, floor, or opening with timber or proprietary props to hold it while people work near it or rescue from it; specialist work above a certain point.
Raker, dead shore, flying shore: the three common forms of prop, against a leaning wall, under a sagging floor, and across a gap between two walls; named here for understanding, applied only under qualified instruction.
Partial collapse: the fall of part of a damaged structure, the gravest hazard of disaster works, because what stands after a first collapse is disturbed, loaded oddly, and far more likely to fall again.
Make safe first: the rule that before any work or rescue, the scene is assessed and the immediate dangers are removed or guarded, so that helpers do not walk into the next casualty.
The buddy system: the discipline of never working alone on a disaster site, so that each person is watched, a second judgement is present, and help is at hand if something gives way.
Second casualty: the rescuer who is hurt or killed in the attempt, turning one casualty into two, stalling the task, and drawing help away from the person in need; the thing every safety rule in this lesson exists to prevent.

The pioneer in a disaster, under the civil authority

When a flood or a storm overwhelms what the civil services can manage alone, the Army is called to help, and the pioneer's tasks are broadly known in advance. The force raises and repairs flood banks, fills and lays sandbags, builds expedient barriers, and pumps and channels water away. It shores up buildings a storm has weakened so that people can be reached or the structure made safe. It clears the debris that blocks a road, dams a stream, or traps a person. This is plain, heavy, decisive work, and a stricken civil service, suddenly stretched past its limit, has nothing it needs more than a disciplined body that will turn out, take direction, and keep going.

All of it is done under the rule that governs the whole Aid to the Civil Power course: the Army aids and never supplants the civil power. The civil authorities and the emergency services lead the response and hold primary responsibility for the affected population; the pioneer fills the gap they cannot close, with what a military does well, engineering, manpower, and organised effort, without taking over the relief or displacing the agencies whose task it is. The right instinct on arriving at a flooded street is not to start directing a defence because no one else seems in charge, but to find the civil authority who leads, report in, and take the task they give. For any task, a pioneer should be able to answer the same plain questions: who requested this help, who authorised it, what is the defined task and where does it end, and when does the authority run out.

There is a particular reason this matters for engineering work. A sandbag wall placed wrongly does not merely fail to help; it can send water where the civil plan meant to keep it out, flood a property the authorities were holding, or weaken a bank they were building up. The pioneer who freelances a flood defence may undo a larger plan they cannot see. So the engineering judgement and the constitutional rule meet at one point: you build where you are told to build, to the design you are given, as part of one plan run by the people who can see the whole of it.

Flood works: filling, placing, and bonding the sandbag wall

The sandbag is the pioneer's commonest flood tool, and it is more often used badly than well. A heap of loosely thrown, over-filled bags is not a wall; it is a pile that leaks at every joint and slides apart under the push of the water. A sandbag wall holds back water only when each part of it is done correctly, and the parts are simple enough to learn but unforgiving if skipped.

Fill the bag to about half or two-thirds, not full. This is the error most often made. An over-filled bag is round and hard; it will not settle, will not mould to its neighbours, and leaves gaps a finger could pass through, and water passes through gaps. A bag filled to about half is floppy; it slumps when laid, beds down onto the bags below, and packs against its neighbours so the joints close. Fold or tuck the open end under the bag rather than tying it, so the weight of the bag holds it shut and the folded end faces away from the water. Use a sandy or earthy fill that packs; avoid stones, which leave voids.

Lay the bags as a bonded wall, not a stack. Lay the first course flat, lengthways, on cleared and, where you can, slightly hollowed ground, treading each bag down so it beds. Lay the next course so its joints fall over the middle of the bags below, exactly as a bricklayer staggers the joints, and tread it down onto the course beneath. This staggering is called bonding, and it is what turns separate bags into a single mass that resists the water as one. A wall whose joints line up vertically is a set of loose columns that shear apart at the first real push; a bonded wall holds together. Step the wall back slightly as it rises, and keep it no higher than about three courses unless it is built as a proper bank with a broad base, because a sandbag wall, being only stacked bags, has very little strength against being pushed over.

   THE SANDBAG WALL: BONDED COURSING (the right way)

   WRONG: joints in line          RIGHT: joints staggered (bonded)
   (loose stacks, they slide)     (one mass, it holds)

   [==][==][==][==]               [==][==][==][==]
   [==][==][==][==]                 [==][==][==][==]
   [==][==][==][==]               [==][==][==][==]
   [==][==][==][==]                 [==][==][==][==]
    |   |   |   |                  staggered like brickwork:
    weak vertical joints           each joint sits over a bag

   - Fill bags HALF to TWO-THIRDS, never full (floppy beds down).
   - Fold the open end UNDER, facing AWAY from the water.
   - Tread EACH bag down onto the one below.
   - STAGGER the joints course over course (this is BONDING).
   - Step the wall back as it rises; keep it low and broad-based.

                <<<  W A T E R   S I D E  <<<
         line the water face with plastic sheet,
         tucked under the foot, to seal the wall.

Seal and key the wall. Even a well-built sandbag wall seeps, because water finds every joint. Where you have plastic sheeting, lay it against the water face of the wall and tuck its lower edge well under the foot of the wall on the water side, weighted by the bottom course, so the water pushes the sheet against the bags and seals them rather than lifting it. Key the wall into the ground at the foot and into any solid thing at its ends, a wall, a kerb, a doorframe, so the water cannot simply run round the end, which it will find in a moment if you leave a gap.

Expedient barriers, protecting a key point, and the limits of a wall

Sandbags and time both run short, and the pioneer must often improvise. The principles stay the same, a sealed face, a bonded or solid body, keyed ends, but the materials are whatever is to hand. A length of plastic sheet laid across the line of the water, its upstream edge weighted under a row of bags or earth and its body laid up the slope, makes a cheap and quick barrier where the water is shallow. Earth-filled containers, builders' bags, bins, boxes, set in line and sealed with sheet, hold back more for less filling. A door or a low opening can be dammed with a board set across the frame and bedded against bags or earth on the water side. None of these is as good as a properly built bank, but each can buy time, and time is often what the civil plan needs.

Protecting a doorway or a key point is the commonest small flood task, and it has a shape. Decide first whether to keep the water out or let it in and protect what matters; sometimes a low building cannot be held and the better work is to lift or move what would be ruined and let the water through a building it cannot harm. Where you defend a doorway, build the barrier outside the threshold so the water bears on the building and not on a loose dam, key it hard into both sides of the frame, seal the face with sheet, and remember that water under the floor and up through the drains will defeat a barrier across the door, so a pump inside may be needed as well as a dam outside. For a key point, a pump house, a substation, a clinic, the same logic applies on a larger scale, and the task is given by the civil authority who knows which points must be held.

Above all, know the limits of what a sandbag wall can hold. A sandbag wall is a low, temporary barrier against a modest head of water. It is not a dam and will not hold back a deep or a fast flood, and the deeper the water behind it, the harder it pushes and the more likely it is to slide, topple, or be undermined as the water works beneath its foot. Moving water carries a force far greater than its depth suggests, and a wall that holds a still flood may be swept by a flowing one. The honest judgement, which the pioneer must be ready to give and the civil authority to hear, is that some water cannot be held by bags and the work then is not to defend the indefensible but to warn, to move people and what matters out of its reach, and to let the flood take ground that bags were never going to save. A pioneer who understands the limit serves the plan; one who does not may keep a doomed wall manned until the water takes it, and the people with it.

Shoring and propping a damaged structure

A storm, a flood, or a collapse leaves buildings that are still standing but no longer sound: a wall leaning, a floor sagging, a roof part-fallen, an opening that wants to close. Where someone must work near such a structure, or be reached and rescued from it, it may be shored, temporarily propped to hold it while the work is done. Shoring is real engineering, and this lesson teaches it for understanding and for the safe limit of the pioneer's part, not as something to be improvised for real on the strength of the reading. The certified practical instruction, under qualified supervision, is where shoring is actually learned, and beyond a certain point it is specialist work the pioneer hands on rather than attempts.

There are three common forms, named here so you know what you are looking at. A raker is a prop set at an angle against a wall that is leaning or pushed out, its foot braced against solid ground or a sole plate so it pushes the wall back true and holds it. A dead shore is a vertical prop set under a sagging floor or beam, on a firm sole plate spreading its load, to carry the weight while the floor is unsafe. A flying shore is a horizontal prop set across the gap between two walls, bracing one against the other, used where there is no ground between them to brace down to, as when a building between two others has gone. In every case the prop must bear on something solid at both ends, a sole plate to spread the load on soft ground, and be set so it actually carries or restrains the structure and is not merely leaning against it.

   THREE FORMS OF PROP (for understanding; learned in person)

   RAKER                 DEAD SHORE             FLYING SHORE
   (leaning wall)        (sagging floor)        (gap between walls)

   ||  leaning             ====== floor          ||          ||
   ||\  wall               sagging               ||==========||
   || \                       ||                 ||  brace    ||
   ||  \  prop                || dead shore      ||  across    ||
   ||   \                     ||                 ||  the gap   ||
  =========                 =====                ||          ||
   sole plate               sole plate           wall A     wall B
   on firm ground           spreads load         brace one against
                                                  the other

   Every prop: solid bearing at BOTH ends; sole plate on soft
   ground; set to CARRY or RESTRAIN, not merely lean.

Beneath all of this lies the gravest danger of disaster works: partial collapse. A structure that has already failed in part is the most dangerous of all, because what remains standing has been disturbed, is loaded in ways it was never built for, and is far more likely to fall than an undamaged building. Vibration, the removal of a piece that was holding others, a person's weight, even the wind, can bring down what is left. The pioneer treats every damaged structure as wanting to fall, works under qualified judgement on whether it is safe enough to approach at all, props only to a competent design, and keeps people out from under anything that could come down. When the structure is too far gone, the answer is not a braver prop but the specialist rescue teams whose training and equipment this is, and a perimeter that keeps everyone else clear.

Debris clearance done safely

Clearing debris, the fallen tree across the road, the rubble from a collapsed wall, the wreckage a flood has piled against a bridge, is constant work in a disaster, and it is more dangerous than it looks, because debris is rarely the inert heap it appears. The rule is to assess before you move anything.

The first danger is the load that holds another. A pile of debris is a web of things leaning, wedged, and propping one another, and the piece that looks loose may be the very thing holding the rest. Pull it, and what it was holding falls, onto the pile, onto the road, onto whoever is standing in the wrong place. So before moving any piece, look at what it is bearing and what is bearing on it, work from the top and the outside inward, take the loose and the free first, and never stand where a thing would fall if the piece you are moving lets go. The same caution governs a tree under tension: a trunk bent and trapped is a spring, and cutting it the wrong way releases its force suddenly and with great violence.

The second danger is buried services: power lines, gas, and water under or within the debris. Treat every downed or damaged cable as live and keep well clear; the current can pass through wet ground, standing water, and a metal fence some distance from the cable itself. A smell of gas, or the hiss of an escape, means stop, keep clear, allow no flame, spark, or switch, and get word to the authority and the utility, because a gas-filled space and a single spark is a second disaster. Water mains, drains, and electrical supplies all run through the ground a pioneer is clearing, and the rule is the same as with explosives elsewhere in this course: what is not yours to handle, you do not handle; you find it, mark it, keep people off it, and report it to those whose work it is.

The third discipline is to never work alone, and to keep your own safety and your team's at the front of the task. Wear what protects you, watch your footing on a wet and shifting pile, lift within your strength and use the mechanical aids of Lesson 03 for the heavy loads rather than your back, and keep a clear line of sight and a clear way out. A debris pile can shift without warning, and a person buried in it, or pinned by a load that gives way, needs the help of the team that was working beside them. The pioneer who clears debris alone, in a hurry, without looking at what holds what, is the one most likely to bring the pile down on themselves.

The overriding rule: make safe first, and do not become a second casualty

One rule sits above every technique in this lesson, and it must be learned before any of them: make safe first, and do not become a second casualty. A pioneer who walks into a flooded, broken, hazardous scene and is hurt has not added a helper but a casualty, one more person the stretched services must now rescue, and has drawn help away from those they came to serve. One casualty becomes two, the task stalls, and the person in need is no better off and often worse. Staying safe is not the opposite of helping; it is what makes helping possible.

From this follow four plain disciplines that hold across all disaster works.

   MAKE SAFE FIRST: the scene-assessment sequence

   ARRIVE  ----> [ Is the scene safe to approach? ]
                          |
                  NO      |  Floodwater, gas, live cables, an
                  +-------+  unstable or part-collapsed structure?
                  |          |
                  |          v
                  |     DO NOT ENTER. Keep everyone back,
                  |     mark or guard the hazard, get the
                  |     right specialist help. You help
                  |     most by not becoming the next casualty.
                  |
            YES   v
        [ Assess: what could hurt me, my team, the casualty? ]
                  |
                  v
        [ MAKE SAFE: remove or guard the hazards you safely can ]
                  |
                  v
        [ Work in PAIRS. Take qualified judgement on any structure ]
                  |
                  v
        [ Do the task WITHIN the pioneer's role and limit ]
                  |
                  v
        [ Beyond the limit? HAND to specialist rescue. ]

   The order never changes: SAFE first, then the work.

Assess the scene before you act. Before touching anything, read the scene as the Aid to the Civil Power relief teaching reads it: what is the water doing, is the structure stable, are there cables or gas, what could fall, what could give way underfoot. Make safe what you safely can, guard what you cannot, and only then begin the work. The few seconds spent assessing are the cheapest safety you will ever buy.

Work the buddy system; never work alone. On a disaster site every person is watched by another. A second pair of eyes sees the wall begin to move, the pile begin to shift, the colleague in trouble, and a second judgement catches the rash decision before it is acted on. Tell someone what you are doing and where, and keep your buddy in sight.

Take qualified judgement on any structure. Whether a damaged building is safe enough to approach, to work near, or to enter is not a guess for the willing; it is a judgement for someone trained to make it, and on a serious structure for the specialist rescue teams. The pioneer does not decide a leaning wall is "probably fine" because there is work to do behind it.

Know the limit of the pioneer's role, and hand on what lies past it. The pioneer raises barriers, props to a competent design, and clears debris within safe limits. The cutting of casualties from collapsed structures, entry into unstable buildings, work over deep or fast water, and rescue from confined or buried spaces are specialist tasks, and the most disciplined thing a pioneer can do is recognise the line and hand the work to those whose training and equipment it is. As the Aid to the Civil Power and Emergency Preparedness courses both teach in their own words, knowing what is yours to do, doing it well, and handing on what is not, is the discipline that keeps a soldier a help and not a hazard.

In Practice: The Night the River Rose

A river bursts after days of rain and begins to flood the low streets of a town, and a section is sent, on the lawful request of the civil authority and under its direction, to help. The pioneer corporal, an OR-3, reports in to the civil incident officer who leads, and takes the defined task: hold the line of bags along the lower road to keep the water off the clinic and the houses behind it, and do not, she is told plainly, build across the side lane, which the plan means to let flood. She does not freelance a defence of her own; she builds where the plan tells her, because she cannot see the whole of it and the officer can.

Her section fills the bags to two-thirds, not full, so they bed down, folds the ends under facing away from the water, and lays the wall in bonded courses, each joint staggered over the bags below and each bag trodden down, keyed hard into the clinic wall at one end and the kerb at the other so the water cannot run round. They lay plastic sheet against the water face and tuck it under the foot, and the wall seeps but holds. Where a doorway must be protected they dam outside the threshold and set a small pump inside, because the corporal knows the water will come up through the floor and under the door whatever the dam does. When a resident begs them to bank up a low cottage by the river, the corporal judges the head of water too great for bags, says so honestly to the civil officer, and the better work becomes lifting the family's belongings and getting them out rather than manning a wall the flood would take.

Later, a wall of a flood-damaged outbuilding is leaning over the path the rescue teams must use. The corporal does not prop it on a guess; she has it assessed, a raker is set to a competent design against a sole plate on firm ground, and the path is kept clear beneath until it is judged safe. When a part-collapsed house is found with someone trapped inside, the section does not enter; the corporal keeps everyone back, guards the perimeter, and hands the rescue to the specialist team whose work it is, giving them what they need to know. Through it all the section works in pairs, treats every downed cable as live, stops and reports a smell of gas rather than clearing through it, and keeps itself warm, fed, and rested so it is fit to work again. No one was hurt; no one became the second casualty. The section held the line it was told to hold, handed on what was past its limit, and the work was recorded honestly. The soldiers fired no shot and made no speeches; they helped a flooded town with discipline, skill, and care, and went home, which is the whole of the victory this work offers.

Check Your Understanding

Explain how to build a sandbag wall the right way: how full to fill the bags and why, what bonding means and why it matters, and two things you would do to seal the wall and stop the water running round it. Then state in plain terms the limit of what a sandbag wall can hold, and what the right work becomes when a flood is too deep for bags.
Why is a partial collapse the gravest danger of disaster works, and what does it tell you about how to treat any damaged structure? Describe what shoring is and name the three common forms of prop, and explain where the pioneer's part in shoring ends and the specialist's begins.
Debris clearance means assessing before moving anything. Explain the danger of a load that is holding something else and how you would work a debris pile because of it, and separately explain why you treat every downed cable as live and a smell of gas as a reason to stop. Then state the overriding rule of all disaster work and what the buddy system adds to it.

Reflection (write a short paragraph): This lesson teaches that the pioneer in a disaster must make safe first and never become a second casualty, and that the Army aids the civil power and hands serious rescue to the specialists. Think of a hard moment you might meet: a flood too deep to hold, a leaning wall over the path you need, a person trapped in a building that is no longer sound, a debris pile with a service buried in it. What would the rule to make safe first, the buddy system, and the honest judgement of the pioneer's limit tell you to do, even when the urge to rush in and help is strongest? What does that tell you about how you will prepare yourself, in the calm and on the certified practical instruction, to be a help and not a hazard when the river rises?

Summary

The pioneer's disaster work, holding back floods, shoring damaged structures, clearing debris, is the task the RKA is most likely to do, and it is done under the rule that the Army aids and never supplants the civil power (HCR 210): come on the lawful request of the civil authority, take a defined task under its direction, and hand it back. Know who requested it, who authorised it, what it is, and when it ends.
Build a sandbag wall the right way: fill the bags half to two-thirds so they bed down, fold the ends under away from the water, lay them in bonded courses with staggered joints trodden down, seal the water face with sheet tucked under the foot, and key the ends into something solid. Know the limit: a sandbag wall holds only a modest head of water, and when a flood is too deep the work is to warn, move people and what matters, and let the flood take ground bags were never going to save.
Shoring temporarily props a weakened structure (raker against a leaning wall, dead shore under a sagging floor, flying shore across a gap) so people can work near it or be rescued from it. It is specialist work above a certain point, learned in person and handed on, not improvised on the reading. A partial collapse is the gravest danger of all, because what stands after a first fall is disturbed and far likelier to fall again; treat every damaged structure as wanting to fall.
Clear debris by assessing before moving anything: a piece may be holding others, so work from the loose and the outside in and never stand where a load would fall; treat every downed cable as live and a smell of gas as a reason to stop, keep clear, and report; and never work alone, using the mechanical aids of Lesson 03 for heavy loads.
The overriding rule is make safe first and do not become a second casualty: assess the scene, make safe or guard the hazards, work the buddy system, take qualified judgement on any structure, and hand serious rescue, entry into unstable buildings, and work over deep water to the specialists whose work it is. The casualty you become is one more person the stretched services must save.
Practical skills are certified in person; nothing here is to be attempted on real structures, real water hazards, or real debris on the strength of the reading. The Aid to the Civil Power, Emergency Preparedness and Civil Resilience, and Combat First Aid courses carry the same disciplines further: the civil power leads, the pioneer fits in, and the soldier who knows the limit of the role is the one who keeps helping.

Flood, Storm, and Disaster Works