general information
Manual fire escapes are designed to be climbed into upper floors buildings during rescue operations. Manual ladders are operated manually by firefighters without the use of mechanical energy sources. They are made from wood and rolled aluminum. The stairs are simple in design and easy to use. They are included in the equipment of fire trucks that deliver them to the scene of a fire or emergency.General requirements for the manufacture of manual fire escapes and their certification tests are determined by NPB 171-98.
The following requirements are common to all types of stairs. Step step there should be stairs no more than 355 mm, A width of stairs should be in the light not less than 250 mm
The ratio of the mass of the ladder to its length should not exceed:
- for retractable stairs - 4.5 kg/m;
- for stick stairs - 3.1 kg/m;
- for assault ladders - 2.65 kg/m.
The lower ends of ladder strings, with the exception of assault ladders, must be equipped with pointed spurs or pads to prevent ladders from sliding along the supporting surface.
Each staircase outside The bowstring must be marked with the following information:
- manufacturer's trademark;
- staircase designation;
- serial number according to the manufacturer's numbering system;
- month and year of manufacture.
Product information displayed on the product and explaining the procedure for its use, safety rules and the purpose of functional parts must be written in Russian
Metals whose interaction leads to contact corrosion should not be used in the construction of stairs.
Types of manual fire escapes
Assault ladder
Assault ladder is a manual fire ladder, structurally consisting of two parallel strings, rigidly connected by supporting steps and equipped with a hook for hanging on the supporting surface (Fig. 1).
Photo assault ladder
Assault ladder diagram
Bowstrings 1 and 4 of the ladder are connected by thirteen steps 2 and 5. In addition, they are tightened in five places with metal ties 3 and 6. A hook 7 is attached to the three upper steps. The cross-section of the hook increases towards the tail part, which brings it closer to the body of equal resistance along the bend.
Stairs can be made of wood or metal.
Wooden assault ladder
On the inside wooden stairs On both sides of the steps, steel ropes are laid in grooves, secured to the upper and lower ties. The ropes are designed to prevent accidents when bowstrings break. Shoes are installed at the lower ends of the bowstrings, and tips are installed at the upper ends.
Metal assault ladder
Metal stairs are made from aluminum alloy D16T. The weight of ladders is no more than 10 kg.
Purpose of LS
Assault ladders used by firefighters to climb to building floors through windows or balconies. To ensure safe operation, it is used when working on steep roof slopes.
Purpose: LS is designed for lifting firefighters along external wall on the floors of buildings and structures, to support work when opening the roof on steep roofs, as well as for training sessions and competitions. An assault ladder is most successfully used in combination with a three-legged retractable ladder or a ladder truck.
LS device
Device: The assault ladder consists of two strings connected by thirteen wooden steps, three steel ties (at the ends and in the middle of the strings) and a steel hook attached to the top three steps of the ladder. The lower ends of the bowstrings are pointed and equipped with metal shoes.
Steel hook, with which the ladder is suspended, has a tail and cantilever parts. In the tail section, box-shaped bushings are welded to reduce deformation of the steps. To reduce the mass of the hook, holes are drilled in its cantilever part; increasing the rigidity of the hook is achieved by welded longitudinal metal planes (stiffening ribs).
The shape of the hook ensures equal strength of its structure along its entire length under the action of bending forces, and the teeth prevent sliding along the supporting plane.
Technical characteristics of LS
Stick ladder (LP)
Stick ladder (LP) — manual folding fire ladder, structurally consisting of two parallel strings, hingedly connected by supporting steps.
Photo LP (stick ladder)
Stick ladder diagram
Bowstrings 1 and 2 of the staircase are connected by eight steps 3. The ends of the steps have a metal frame and bushings through which axles pass to rotate the steps. The hinged connection of 4 stages with bowstrings allows them to be folded by moving one string relative to the other.
Some ends of the strings have wooden attachments 5. The other string is removed behind them when folding the ladder. The attachments are attached to the bowstrings with 6 ties and covered with 7 tips. The other ends of the bowstrings are beveled at an angle of 45 degrees and protected metal plates 8.
Folded ladder
When folded, the ladder looks like a stick with rounded and bound ends. The weight of the ladder is 10.5 kg.
Purpose of the drug
Purpose: The LP in the working position is intended for lifting firefighters and their weapons to the level of the height of the stairs (into the first floor window, for working on low altitude), for use as a stretcher for carrying victims; in the folded (transport) position used for punching wooden partitions And door panels, beating plaster and performing other auxiliary work.
LP device
Device: the stick ladder consists of two wooden bowstrings oval cross-section and eight steps, hingedly connected to the bowstrings. A special feature of the ladder is the hinged fastening of the steps in the longitudinal plane of the strings, which allows them to be brought together until they are completely closed when folding the ladder into a stick of oval cross-section.
When folding a ladder, its steps are placed in triangular grooves with inside bowstring A wooden plate is attached to one end of each bowstring using a metal tip and tie. The other end of the bowstring is protected by a metal plate.
Technical characteristics of the drug
Retractable three-arm ladder L 60
Retractable ladder — manual fire ladder, structurally consisting of several parallel-connected bends and equipped mechanical device moving them relative to each other in the axial direction in order to regulate its length. The knees are counted from the top.
Retractable fire ladder
Three-leg retractable ladder– a manual fire ladder, consisting of three parallel-connected elbows and equipped with a mechanical device for moving them relative to each other in the axial direction in order to regulate its length (Fig. 3).
Retractable staircase diagram
Photo of a retractable ladder
Construction of a three-legged staircase
The ladder consists of three telescopically connected elbows 6,7 and 8, an extension mechanism and a stopping mechanism. Each knee consists of two bowstrings connected by twelve steps. The bowstring of the lower knee 8 is tightened at the bottom, in the middle and at the top with ties 3.
The knees are connected to each other by steel brackets 1. The lower ends of the bowstrings of the lower knee have steel shoes 9, and the upper ends of the upper knee have wall stops 4. The middle knee is pulled out by a chain 2.
The retraction mechanism works as follows. The middle knee 7 (Fig. 4) is connected to the low knee 8 by chain 2, which goes around the rollers 5 and the upper block of the lower knee. When the chain moves clockwise, 7 will move upward. The upper elbow 6 is connected by a cable 3 through the block of the middle elbow 7 to the center of the upper block of the lower elbow 8. When the middle elbow 7 is extended, the upper elbow 6 will also move up.
The middle knee in relation to the lower one makes a relative movement. The top knee, in turn, moves relative to the middle knee at speed, while at the same time moving with the middle knee in a transfer motion. Thus, the absolute speed of movement of the upper knee is equal to
If the lengths of all three knees are equal, the absolute speed of extension of the upper knee is equal to twice the speed of extension of the middle knee, i.e.
To fix the extended ladder at a given height, a stopping mechanism is used. It is installed on the bowstring of the second knee on its lower part. The mechanism consists of two parts: a guide square and a stop, as well as a special roller with two stops and a lever.
The knee string is covered by a corner (Fig. 5) on both sides. Shelf 1 is located on the inner wide side of the bowstring. Shelf 2 is located on the narrow side of the bowstring, protruding from it by 10 mm. This protruding part fits into the tongue of the first bend and serves as a guide. The bent part 3 faces the inside of the ladder and is a stop for the stopping mechanism. Angles are installed on both strings. Holes 4 in them serve as bearings for roller 1 of the stopping mechanism (Fig. 6). At the ends of the roller 1 there is one cam 4, which in combination with stops 2 (item 3 in Fig. 5) secures the extended knees.
In the middle of the roller at an angle of about 45 degrees to the cavity of the cams there is a protruding pin 6 with an eye at the end. The end of chain 7 is attached to this eye (item 2 in Fig. 4).
If, in a vertical position of the ladder, the chain is pulled down counterclockwise, then roller 1, as well as cam 4, will rotate so that they find themselves in the plane of the steps of the second knee and will not interfere with the extension of the ladder knees.
To secure the knees of a ladder extended to a given height, it is necessary to abruptly pull the chain in the opposite direction, i.e. down up. In this case, the knees of the ladder will begin to shift and, in addition, the roller 1 will rotate. In this case, the finger 6 will go down, and the cams 4 will rise up to the stop 3.
When moving the knees, the cams 4 will meet the step 8 of the first knee on their way, rest against them and delay the movement of the ladder. In this case, the entire load is transferred to stage 8 of the first knee.
Purpose of a retractable ladder
Purpose: The three-legged retractable ladder is designed for lifting firefighters and fire-fighting equipment into the window of the second, third floor of a building, into the attic and roof of a two-story building, for evacuating people, for working indoors (in halls), as well as for training sessions and competitions.
Ladder extension height
Retractable ladder consists of three telescopically moving elbows made of the same type of profiles and parts, an extension and stopping mechanism.
Each knee consists of two posts T-section, connected by steps (corrugated pipes). Each elbow has 12 steps, reinforced in the racks using the rolling method.
Technical characteristics of a retractable three-leg ladder
Scope and rules of application
WHEN INSTALLING A TRADITIONAL FIRE EVADS, YOU MUST:
- install a retractable ladder 1.5 - 2 meters from the wall, the angle of inclination of the ladder is 80 - 83 degrees;
- push out the knees of the retractable ladder evenly, without jerking, without allowing;
- maintain the balance of the retractable ladder during its extension;
- check the locking mechanism in the extended position.
hold the retractable ladder when extending beyond the bowstrings of the first knee, preventing your fingers from reaching the inside of the bowstring;
CLIMBING OR DESCENTING THE EXTENSIONAL LADDER IS ALLOWED AFTER:
- the cams of the stop roller rested on the knee step of the retractable ladder;
- the retractable ladder is leaned against the building (structure) and is supported by the strings of the first knee by the fireman;
the retractable ladder is extended to such a length that it is above the eaves of the building, window sill, etc. at least two steps of the upper knee protruded.
WHEN WORKING WITH AN EXTRACTIONAL LADDER YOU SHOULD:
- install it, as a rule, in places where, in the event of tilting or falling, it will not come into contact with the lines of electrical and radio networks. If this is not possible, it is necessary to allocate three people to install and clean the retractable ladder, one of whom must remain to secure the climbers and the extended retractable ladder from falling until the work is completed;
- installation of a retractable ladder to metal roofing the object is allowed to be carried out only after the enterprise has been de-energized.
When ascending (descending) a retractable ladder, you should look ahead, grasping the steps with your fingers. When conducting classes to train personnel of GPS units to work with assault and three-legged ladders, personnel from GPS units are posted on the training tower floor platforms to provide assistance to students.
Classes on climbing to the floors of a training tower using assault and retractable ladders are carried out only after the leader of the classes personally checks the condition of the belay device, the safety cushion of the training tower, and instructs the people allocated for belay on the floors. All types of work are performed in combat clothing and helmets.
WHEN WORKING WITH MANUAL FIRE ENVIRONMENTS IN CLASSES, EXERCISES OR A FIRE, IT IS NECESSARY:
- do not allow more than one person to climb and descend on one knee of a retractable ladder, as well as an assault ladder and a stick ladder;
hold the retractable ladder while people are ascending or descending it. When working on a ladder with a barrel or tool, the person working with the barrel or tool must be secured to the steps of the ladder using a fireman's belt carabiner;
When climbing a retractable ladder with a tool, take measures to prevent it from falling.
During the period when the personnel of the GPS units undergo special initial training, their work on climbing to the floors of the training tower using an assault ladder without the use of a belay device is not allowed.
Possible faults
IN THE PROCESS OF WORKING WITH STAIRS AND WAYS TO ELIMINATE THEM
| Fault name | Probable Cause | Elimination method |
| 1) The ladder does not extend or move | The rope has become jammed between the blocks | Remove the rope and place it in the clip. Adjust the gap between the block hub and the race. |
| 2) Extension and sliding occurs with distortion or with great resistance | The normal clearances between the front stops of the struts or the strut and the rear stops are broken | Adjust the gaps by sawing the rear or front stops |
| 3) The ladder does not fix its position when extended | Stop mechanism does not work | Replace springs or repair hooks |
Test procedure and timing
- Manual fire escapes should be tested once a year and after each repair.
- Before using them in competitions, certificates must be submitted.
- The use of manual fire escapes that have malfunctions, damage to main parts or have not passed the test is not permitted.
During testing, it is installed on solid ground, leaned at an angle of 75 degrees. to the horizontal and loaded in the middle with a load of 120 kg for 2 minutes. After removing the load, the ladder-stick should not have any damage and should fold easily and tightly.
Stick ladder tests
When testing, the assault ladder is suspended freely by the end of the hook and each string at the level of the 2nd step from below is loaded with a load of 80 kg (160 kg in total) for 2 minutes. After testing, the assault ladder should have no cracks or residual deformation of the hook.
Assault ladder tests
When tested installed on solid ground, extended to full height and leaned against the wall at an angle of 75 degrees. to the horizontal (2.8 m from the wall to the ladder shoes). In this position, each knee is loaded in the middle with a load of 100 kg for 2 minutes. The rope must withstand a tension of 200 kg without deformation.
Checking the steps
Literature:
- Norms fire safety NPB 171-98* “Manual fire ladders. General technical requirements. Test methods;
- Federal Law of July 22, 2008 N 123-FZ “ Technical regulations on fire safety requirements”;
- Textbook for higher educational institutions Ministry of Emergency Situations of Russia M.D. Bezborodko, S.G. Tsarichenko, V.V. Roenko, N.I. Ulyanov, M.V. Aleshkov, A.V. Rozhkov, A.V. Ploskonosov, S.A. Shkunov, V.M. Klimovtsov, S.P. Khramtsov “Fire and rescue equipment” Moscow 2012.
Manual fire escapes- portable design included in the fire-technical weapons fire truck and designed to support fire extinguishing operations and related ASR activities at height. Manual fire escapes are one of the most commonly used firefighting equipment. In our country, the following three types of manual fire escapes are in use: retractable fire escapes , stick ladders , assault stairs. A retractable ladder is a manual fire escape, structurally consisting of several parallel-connected elbows and equipped with a mechanical device for moving them relative to each other in the axial direction in order to regulate the length of the ladder. The knees are counted from the top. This ladder is designed to climb firefighters and fire-technical weapons on the second and third floors of buildings when extinguishing fires, as well as for carrying out emergency control in buildings, structures and production facilities of various sectors of the national economy. dimensions, mm: length when folded 4380 (+/-) 30, length when fully extended 10700 (+/-) 30, width 480 (+/-) 5, height when folded 202 (+/-) 5, distance between steps 340 (+/-) 5 mm. Effort when extending the ladder, height no more than 400, weight no more than 50 kg. An assault ladder is a manual fire escape, structurally consisting of two parallel strings, rigidly connected by transverse support steps and equipped with a hook for hanging on the supporting surface. Designed to support the actions of personnel when extinguishing fires and conducting related emergency control operations at height. It is used to lift firefighters along the outer wall of buildings and structures, as well as to support work when opening the roof on steep roofs. Overall dimensions, mm: length 4110 (+/-) 5, width 300 (+/-) 3, hook reach 652 (+/-) 34, weight no more than 10.0 kg; the distance between the steps is no more than 340 mm. Stick ladder is a manual folding fire ladder, structurally consisting of two parallel strings, hingedly connected by supporting steps. Designed to support actions during fire extinguishing and related ASR at height. The ladder is used to lift firefighters into the windows of the first floor of the building. Linear dimensions, mm: working position: length 3116 (+/-) 10, width Z46 (+/-) 5, clear width 250 (+/-) 5; transport position: length 3400 (+/-) 10, width 105 (+/-) 5, step between steps no more than 340 mm, weight no more than 10.5 kg. Stairs are made in most cases from metal, but wooden and, more recently, fiberglass structures are also available.
