Service platform for an electric crane. Installation of bridge cranes. Crane track mounting process

For each overhead crane and mobile console, equipped with a control cabin, a landing platform must be arranged for access from the workshop floor to the cabin. The distance from the floor of the landing site to the lower parts of the structure located above the floor must be at least 1800 mm.

The layout of the first version of the landing site is shown in Fig. 4. 11. The entrance to the cabin from such a platform is carried out from the longitudinal side of the hull or overpass (from the side of the colony), and its flooring is located on the same level with the floor of the cabin or vestibule, when the cabin is equipped with a vestibule. It is allowed to set up a landing platform below the level of the cab field, but not more than pa 250 mm, in cases where, when it is located at the same level with the floor of the cab, the dimensions (1800 mm) in height cannot be maintained. The gap between the landing area and the threshold of the cab door (vestibule) should be in the range from 60 to 350 mm.

Rice. 4 11. Layout of the landing site (option 1).

Landing pads according to the second option (Fig. 4. 12) are arranged at the end of the crane runway with access to the cabin from the side of the building end.

For such a platform, it is allowed to run over a cab on it, no more than 400 mm with fully compressed crane buffers. In this case, the gap between the platform flooring and the lower part of the cab (vertically) must be at least 100 mm and not more than 250 mm, between the cab and the landing pad fence - at least 400 mm, and from the side of the cab entrance - at least 700 mm.

For landing sites made according to the second option, it is impossible to bring the fence closer to the cabin by less than 400 mm, since this can be the cause of an accident: a person standing at the railing of the fence can be pressed by the cabin or knocked down when it hits the site. To prevent the crane operator from falling into the gap between the fence and the cab, the entrance to the cab should be provided from the side farthest from the edge of the platform.

The device of landing sites providing for landing in the cabin through the bridge (crane girder) is allowed only in justified cases when the implementation of landing sites for direct landing in the crane cab is difficult for structural or production reasons (for example, when the cranes are located in two or three tiers, fastening cabs to the crane trolley, etc.). In this case, the entrance to the crane must be provided in a specially designated place, through a door in the railing of the bridge, equipped with an electrical interlock. The device of such an entrance at magnetic taps is permissible only if the blocking does not de-energize the trolley wires supplying it, are located in a place of the crane inaccessible to contact, or are fenced off (Article 233 of the Rules for Cranes).

To enter the cockpit across the bridge, landing sites must also be arranged. It is allowed to provide for such a landing from a common passage gallery (if it has a width of at least 500 mm and is fenced with a railing from the side of the crane runway).

Rice. 4. 12. Layout of the landing site (option 2) a - cockpit

In this case, a certain place is allocated for each crane on the gallery and a transitional staircase with a landing platform is arranged. The approximate height of the end beams of general-purpose electric bridge cranes, according to which the height of the landing sites for entering the cabin through the bridge is determined, can be taken from Table. 4.7 and fig. 4.13.

Table 4.7 Height of end beams

When arranging landing sites, one more very important safety requirement should be fulfilled: the landing site fastening structures located at a height of more than 1 m from its flooring must be at least 400 mm away from the cabin.

Figure 4.13. End beam diagram

Figure 4 14. Variants of the platform for access to the bridge deck: 1 - platform; 2 - stop: 3 - opening in the railing of the bridge; 4- side of the crane travel mechanism

The specifics of the landing pad arrangement for direct entry into the cab suspended from the crane trolley is not reflected in the Crane Rules. In this regard, the gaps between the platform and the cabin when the latter approaches the platform should be taken taking into account the safety of using the platform and preventing damage to the platform by a possible collision of the cabin.

The cab, which is suspended from the crane trolley, can be entered through the bridge deck, subject to specific requirements.

Figure 4.15. Landing pads. a - option 1; b - option 2; c - option 3; d - option 4; d - option 5

Landing pads should be located on the side where the main trolley wires do not pass. An exception is allowed in the case when the trolley wires are not accessible for accidental touch of people on the stairs and landings.

For access to the gallery (platform) of overhead cranes that are not equipped with a control cabin (controlled from the floor or remotely), platforms with a ladder must be arranged, the installation of which can be done according to one of the following options:

a) the platform and the staircase are located in the plane of the building columns, and the entrance to the bridge is made from the end of the crane through the end beam (Fig. 4. 14, a). The platform is marked at the height of the head for the crane rail plus the height of the end beam. The arrangement of the site according to this option should be linked to the construction part of the hull project. The height of the end beams should be taken according to table. 4. 7. The exit from the site to the crane runway must be closed;

b) the platform is installed at the end wall of the building, and the exit to the park is made from the front of the bridge, for which an opening is made in the railing of the crane gallery (Fig. 4. 14, b). The platform is located at the level of the crane rail head. When arranging such a platform in the installation drawings of the crane, it is imperative to indicate the side of the crane where the platform for the crane mechanisms is located. The entrance to the tap can only be arranged from this side;

c) if there is a passage gallery along the crane runways, the entrance to the crane bridge can be made from this gallery through the end beam of the crane.

In all three versions, the door in the railing of the crane bridge must be electrically interlocked.

Approximate designs of landing sites are shown in Fig. 4.15.

When developing a project, the actual dimensions that determine the position of the crane cab are not always available, therefore, the working drawings of the landing sites should indicate: "When installing the landing site, it is necessary to clarify its vertical elevation and horizontal position according to the actual binding of the crane cab".

The need to arrange special platforms for inspection and maintenance of mechanisms located outside the crane, the Crane Rules (Article 229) provide only for single-girder (supporting and overhead) and double-girder suspension cranes, if they are installed in the building and do not have platforms and galleries located on the very tap. In other cases, the expediency of arranging sites is determined by the organization designing the installation of cranes, or by the enterprise that operates them.

The platforms can be stationary or mobile. In stationary platforms, the distance from the flooring to the lower gauge of the crane being serviced should be at least 1800 mm, however, at this distance, access to the mechanisms is very difficult. To create normal service conditions, this distance can be reduced, provided that there is a locking door on the stairs with automatic electrical interlocking, which removes voltage from the main trolley wires of the repair area.

The staircase must have a door, opening which automatically de-energizes the trolley section in the area of ​​the site. The switching on of the trolls after the repair of the crane is made by the breaker of the repair zone. Wiring diagram for blocking the entrance to the repair site, see 7.13.

Approximate solutions for stationary repair sites are shown in Fig. 4.16-4. 22.

The requirement for the door of the repair site for single-girder and double-girder overhead cranes, when the distance from the floor of the repair site to the lower parts of the crane is less than 1800 mm and when the conductor to the crane is carried out not with trolley wires, but with a flexible cable. In this regard, the need for a blocking device to automatically remove stress from the flexible cable in this case

Figure 4.18 Repair area at the end of the span for single-girder electric bridge cranes controlled from the cab with a lifting capacity of 1-5 tf with a span of 4.5 to 10.5 m: 1 - platform; 2 - chain; 3 - emphasis; 4 - cabin

should be determined taking into account the number of cranes operating in one span, the way the cranes are operated (from the cabin or from the floor) and the possibility of taking other measures to prevent people from entering the repair site during the operation of the cranes and running over them. The repair site is designed for a uniformly distributed load of cranes 20U kgf / cm2, and the site area assigned

Figure 4.19. Repair site at the end of the span of single-girder electric bridge cranes controlled from the cab with a lifting capacity of 1-5 tf with a span of 13.5 to 23.5 m (1-4, see Fig. 4.18):

for the repair of an electric hoist, on the concentrated weight of an electric steel of the corresponding carrying capacity. For two girder overhead traveling cranes, it is advisable to provide in the repair car (see 7. 5) platforms for inspection and change of the traveling wheels of the crane, if there is a distance of at least 600 mm from the end part of the crane to the wall of the building. Access to such sites is provided from the crane bridge or through a hatch in the deck, which is closed during the operation of the cranes. Access to such a repair site is carried out according to a permit.

Overhead cranes controlled from the cab (except for single-girder and overhead cranes) must be equipped with cabins for servicing the main trolley wires and current collectors, if they are located below the deck deck of the bridge (Article 230 of the Crane Rules). The hatch for entering from the bridge deck into this cabin must be equipped with a lid with a lock.

The dimensions of the cab for servicing the main trolleys and their pantographs are not regulated and are usually taken 1000X1400 with a height of at least 1800 mm. It is not necessary to take the area of ​​the cabin less than 800X800 mm. The cabin must be fenced with a handrail with a height of at least 1 m with continuous filing along the bottom for a height of 100 mm. It is suspended at a distance of 1000-1100 from the axis of the crane rail. When the cable is supplied with current, the cabins are not arranged. The floor of the cab is covered with a dielectric mat.

Figure 4.20. Repair site for suspended two and three-span electric single-girder cranes with a lifting capacity of 1-5 tf (1-3 - see Fig. 4.18)

The size of the galleries is regulated by the Crane Rules. The width of the free passage through the gallery should be:

a) for cranes with a transmission drive - not less than 500 mm;

b) for cranes with a transmissionless or manual drive - at least 400 mm.

For the same cranes on galleries intended for the location of trolley wiring, the width of the passage between the railings and the devices supporting the trolleys, as well as current collectors, must be at least 400 mm.

The requirements of the Rules for cranes do not apply to the gallery of the overhead crane located on the side of the current supply, if the current supply to the electrical equipment of the trolley is made with a flexible cable. The cantilever holding the cable can traverse the entire width of the bridge gallery. The hatch for the exit to the bridge deck of such a crane must be equipped with an interlock that automatically relieves the voltage from the flexible cable when entering the bridge deck.

The distance from the end railing of the crane bridge to the protruding parts of the cargo trolley when it is in the extreme position is not regulated. This distance is sometimes taken to be less than 400 mm to increase the crane's service area. All these requirements also apply to gantry cranes and mobile jib cranes.

Overhead cranes controlled from the cab (except for single-girder and overhead cranes) must be equipped with cabins (platforms) for servicing the main trolley wires and current collectors, if they are located below the deck deck of the bridge. The hatch for entering from the bridge deck into this cabin must be equipped with a lid with a lock.

The dimensions of the cabin for servicing the main trolleys and their pantographs are not regulated and are usually taken 1000 x 1400 (PTO Komsomolsk-on-Amur plant) with a height of at least 1800 mm. It is not necessary to take the area of ​​the cabin less than 800 x 800 mm. The cabin must be fenced with a handrail of at least 1 m height with continuous filing along the bottom to a height of 100 mm. With a flexible current supply, the platforms are sometimes not arranged.

The crane bridge must be fenced on the four outer sides (along the perimeter) with a 1 m high handrail with a continuous fence at a height of at least 100 mm to prevent the fall of tools or parts during inspection and repair of crane mechanisms and electrical equipment.

Railings are not installed on the side of the cart on the galleries of the bridge and end beams.

In this regard, it is dangerous to be on the bridge of a crane made of lattice girders, in which the gallery floor is located at the level of the trolley rails, as it is possible to fall into the span between the trusses. Cases of people falling from a crane bridge have been reported exclusively on lattice girder cranes. In addition to the noted drawback (lack of proper fencing of galleries), on such cranes the passage along the floor is constrained due to the location of movement mechanisms on it, which also poses a danger to the service personnel. For cranes with box girders, the gallery deck is located below the level of the bogie rails, so passage through such galleries is not dangerous.

To prevent accidents on cranes of old structures, where the passage through the gallery is constrained, it is necessary to arrange bypass platforms at the locations of the electric motor and gearbox of the bridge movement mechanism or transitional bridges with handrails. Precautions should also be taken to ensure that the worker's feet do not slip on the deck when crossing.

The installation of handrails along the bridge from the side of the trolley causes difficulties in the maintenance and repair of the trolley mechanisms, since it is necessary to climb over the handrails.

The crane trolley must be fenced from the end sides with a 1 m high rail with a continuous filing at the bottom to a height of 100 mm. The railing on one of the longitudinal sides of the trolley should be installed if there is no gallery on that side along the crane bridge, for example, with a flexible current supply to the trolley.

For trolleys and end beams, it is allowed to reduce the height of the handrails if the dimensions of the building do not allow the installation of handrails with a height of 1 m.

In accordance with the Rules for the convenient and safe maintenance of cranes, their mechanisms and electrical equipment located outside the cab, it is planned to arrange appropriate galleries, platforms and stairs.

Landing pads. To enter the crane operator into the crane control cabin, landing platforms with permanent stairs are arranged. Landing pads are of two types: end and intermediate. The end ones are arranged in a dead end at the end of the span, near the wall of the building. Intermediate - when working in one span of several overhead cranes on a technologically advantageous, convenient and safe section of the way of their work.

The safest landing sites are located at the end wall of the building. Therefore, if no more than two cranes operate in the span on one crane runway, they should be placed at both ends of the building. Intermediate landing sites located along the workshop aisle require special attention during operation. Due to the small distance between the cab and the platform, there is a risk of injury to people.

At one of the factories, a team of auxiliary workers in the foundry shop used an intermediate landing site to whitewash the building. At the end of the work, the plasterer lowered the spray gun and hoses to the floor of the workshop. At that moment, an overhead crane passed by and injured a worker with the cabin.

An important requirement of safety regulations for the design of landing sites is to place them on the opposite side of the trolley wires. An exception, as in the placement of crane cabins, is allowed only when the trolley wires are inaccessible for accidental touching them from the landing site, stairs, cabins. The landing site must be free enough and comply with the Rules.

The distance from the floor to the lower parts of the ceiling or protruding parts of structures is at least 1800 mm. The deck floor must be level with the car floor for a normal and safe transition from deck to car and vice versa. The gap between the car and the platform must be at least 60 mm and ns more than 150 mm. Sometimes it is allowed to set up a landing area below the level of the cabin floor (no more than 250 mm), if when the landing area is located at the same level with the cabin floor, it is impossible to ensure the overall size (1800 mm) in height. It is also allowed to run over to the platform (no more than 400 mm) with fully compressed buffers, if the landing platform at the end of the building is made below the level of the cabin crawling. The rules stipulate that the following clearances must be observed:

between the landing area and the lower part of the cabin (vertically) - not less than 100 mm:

not less than 400 mm between the cab and the landing pad;

from the side of the entrance to the cab - not less than 700 mm.

In some cases, when direct entry into the crane cabin is impossible for structural or other production reasons, with the knowledge of the local authorities of Gosgortekhnadzor, it is allowed to enter it through the crane gallery. When the door is opened, the zip lines running along the crane bridge are automatically de-energized in the gallery fence.

When the main crane trolls are located above the level of the crane runways, landing on the crane is allowed only from the side where the main trolley wires do not pass; in all cases at the crane stand they must be protected with a shield made of insulating material. The entrance to the cabin is through the bridge of the crane, which has. lifting and transport operations are carried out using an electric magnet and the location of the trolls to power the magnet does not exclude accidental touching them, it is prohibited.

Galleries. The flooring of galleries, all repair and other sites should be metal, from steel corrugated or perforated sheets with holes no more than 20 mm. At the same time, the Rules allow the construction of a wooden flooring if it is strong enough and meets fire safety requirements. Metal or wood flooring should be laid along the entire length and width of galleries, platforms, walkways. All galleries and platforms intended for servicing cranes, as well as the end beams of overhead cranes, must be fenced with a 1 m high railings with a continuous lining at the bottom with a protective strip with a height of at least 100 mm. Galleries for passage along the crane runways must meet the above requirements and have comfortable, safe ladders. The walk-through gallery has a railing on the side of the span and on the opposite side, if it is not limited by a wall. The passage width is at least 400 mm, and the height is at least 1800 mm. For electrical safety of people, the galleries are located on the side of the span opposite the trolls. The most successful should be the device of a light transition gallery, located above the level of the crane runways with special passages in the metal columns of the building. It is not allowed to leave an unenclosed section of the gallery near the columns. When arranging a passage inside the column 1 m before approaching it, the width of the passage through the gallery is reduced to the width of the passage in the column.

Each gallery must have exits at least 200 m apart. If there are impassable crane runways (unenclosed passage less than 400 mm), people are prohibited from staying on them.

6. How is the replacement or re-packing of ropes arranged?

Steel wire ropes must be replaced if one of the strands is broken or the number of broken wires in the length of one lay step exceeds the values ​​indicated in table. 52. The permissible number of broken wires depends on the diameter of the rope. Calipers are used to determine the diameter of the rope (see Fig. 65, a). To determine the pitch of the twist, a mark is made on the surface of the rope and the number of strands available in the section of the rope (for example, six in a six-strand rope) is counted along the central axis of the rope, and a second mark is applied to the next strand after the end of counting. The distance between the marks is equal to the pitch of the rope.

The choice of a rope with a certain direction of lay is made depending on the direction of laying its turns on the drum. If both ends of the rope are attached to the cargo drum, then the direction of the rope can be twisted.

Sharp bends and loops contribute to the destruction of the rope, therefore, when unwinding it, loop-like bends should not be allowed. When unwinding, the rope must be laid in coils or wound on spools, the diameter of which must be at least 20-25 rope diameters. The rope comes from the manufacturer in pieces of 250, 500 and 1000 m long. To obtain a rope of the required length, it is tied with steel wire with a diameter of 1-2 mm, and then cut. The length of each wire tie on the rope should be the diameter of the rope.

The results of tensile tests, twisting and bending of the rope wires will satisfy the requirement of at least 1.5-2.0 rope diameters, and the distance between the dressings is three to four lines of GOST 3241-80, if the total cross-sectional area of ​​the wires, not the requirements of the standard, is not more than 5% of the nominal area corresponding and the cross-section of all wires in the rope when testing 100% of the wires, not more than 2% of the nominal cross-sectional area of ​​the rope when testing 25% and 10% of the wires in the rope. It is allowed to retest all the wires of the rope if non-compliance with the requirements of GOST 3241-30 is found.

7. What should I do if the sling is jammed when placing the load?

195. The crane must have easy access to the cab. Overhead cranes must have a safe exit to the crane trolley. For single-girder and double-girder suspended overhead cranes, galleries or platforms on the crane are not required if there is a repair platform in the span in which it is installed.

196. On bridge-type cranes and mobile jib cranes in the presence of a gallery intended for servicing electrical equipment and mechanisms, the free passage width should be:

A) in the area of ​​movement mechanisms with central drive - not less than 500 mm;

B) in the area of ​​movement mechanisms with a separate drive - not less than 400 mm.

In the area where trolleys are located, the width of the passage between the railings and the devices supporting the trolleys, as well as current collectors, must be at least 400 mm.

In the spans of buildings in which overhead bridge cranes with a classification group (mode) A6 are installed, as well as on ramps for cranes (except for single-girder and double-girder overhead cranes), galleries must be arranged for passage along the rail track on both sides of the span.

197. Galleries for passage along the track should be equipped with handrails on the side of the span and on the opposite side in the absence of a wall. The gallery on an open overpass can be equipped with a handrail with a height of at least 1100 mm only from the outside (opposite to the span).

198. The width of the passage (in the light) along the gallery for the passage along the rail track must be at least 500 mm, the height - at least 1800 mm.

199. At the locations of the columns, a passage must be provided on the side or in the body of the column with a width of at least 400 mm and a height of at least 1800 mm. It is not allowed to leave an unenclosed section of the gallery near the columns.

200. When arranging a passage inside the column 1000 mm before approaching it, the width of the passage along the gallery should be reduced to the width of the passage in the column. Each gallery must have access to the stairs at least every 200 m.

201. Repair sites should provide convenient and safe access to crane mechanisms and electrical equipment.

202. If the distance from the floor of the repair site to the lower parts of the crane is less than 1800 mm, the door to enter the repair site must be equipped with a lock and an automatic electrical interlock that removes voltage from the main trolleys of the repair site.

203. Instead of installing stationary repair sites, it is allowed to use mobile sites that can safely withstand the load indicated in their passport.

204. Overhead cranes controlled from the cab (except for single-girder and double-girder overhead cranes) must be equipped with cabins (platforms) for servicing the main trolleys and current collectors if they are located below the crane gallery deck. Cranes with a cable current lead are not required to be equipped with the indicated access means.

205. The hatch for entering from the bridge deck into the cab for servicing the main trolleys must be equipped with a cover with a device for locking it with a lock.

206. The cab for servicing the main trolleys must be fenced with handrails with a height of at least 1100 mm with a continuous lining at the bottom with a height of 100 mm.

207. The size of hatches arranged for the entrance to the flooring of walk-through galleries of repair and other sites should be taken at least 500 x 500 mm. In this case, the hatch should be equipped with an easily and conveniently opening cover.

208. The angle between the hatch cover in the open position and the deck should be no more than 75 °.

209. To enter the control cabin of a bridge crane, a mobile jib crane, as well as an electric cargo trolley moving along an elevated rail track, a landing platform with a stationary ladder should be arranged.

210. The distance from the floor of the landing area to the lower parts of the ceiling or protruding structures must be at least 1800 mm. The floor of the landing area should be located flush with the floor of the cabin or vestibule, if the cabin has a vestibule. The gap between the landing area and the threshold of the cab door (vestibule) when the crane stops near the landing site must be at least 60 mm and not more than 150 mm.

211. It is allowed to arrange a landing area below the level of the floor of the cabin, but not more than 250 mm in the event that when the landing area is located on the same level with the floor of the cabin, the height clearance (1800 mm) cannot be maintained, as well as when the landing area is located at the end of the building and the impossibility of observing the specified gap between the cabin threshold and the landing platform.

212. When arranging the landing area at the end of the rail track below the level of the cabin floor, it is allowed to run over the landing area (but not more than 400 mm) with fully compressed buffers. The gap between the landing area and the lower part of the cabin (vertically) should be within the range from 100 mm to 250 mm, between the cabin and the landing area fence - within the range from 400 mm to 450 mm, from the side of the cabin entrance - within the range from 700 mm up to 750 mm.

213. Entry into the control cabin of an overhead crane through the bridge is allowed only if direct landing in the cabin is impossible for design or production reasons. In this case, the entrance to the crane must be arranged in a specially designated place through a door in the railing of the bridge, equipped with an electrical interlock and an audible alarm.

214. The flooring of galleries, platforms and walkways must be made of metal or other durable materials that meet fire safety requirements. The decking should be arranged along the entire length and width of the gallery or deck.

215. The flooring must be made so as to exclude the possibility of slipping of the legs. When using decks with holes, none of the hole sizes should exceed 20 mm.

216. Galleries, platforms, walkways and staircases, arranged at the locations of trolls or bare wires under voltage, regardless of the presence of entry locks, must be fenced to prevent accidental touching of trolls or bare wires.

217. Platforms and galleries, end beams of bridge-type cranes, intended for access and (or) maintenance of cranes, must be fenced with handrails with a height of at least 1100 mm with a continuous fence at the bottom with a height of 100 mm.

218. On the end beam and trolley of an overhead or mobile jib crane, the height of the handrail can be reduced to 800 mm if the dimensions of the building do not allow the installation of a handrail with a height of 1100 mm.

219. Railings and fences along the bottom should also be installed on the end sides of the bogie of bridge-type cranes, and in the absence of a gallery, along the crane bridge and on the longitudinal sides of the bogie.

220. Racks on the landing area, to which the railings or fastening structures of the landing area are attached, located at a height of more than 1100 mm from its deck, must be at least 400 mm away from the cabin.

221. The end beams of bridge-type cranes, having a width of not more than 300 mm, as well as cranes that use an electric hoist as a lifting mechanism, may not be protected by handrails if, according to the operating manual (instructions), their end beams are not intended for servicing the crane. ...

222. Ladders for access from the floor to platforms and galleries of bridge-type cranes must be at least 600 mm wide. The width of the ladders located on the crane, with the exception of ladders with a height of not more than 1500 mm, must be at least 500 mm.

223. Ladders with a height of less than 1500 mm, located on the crane, as well as ladders for exiting the cabin to the gallery of a bridge-type crane or a mobile console crane, may be at least 350 mm wide.

224. The distance between steps should be no more than 300 mm for steeply inclined stairs and 250 mm for inclined boarding stairs.

225. The step of the steps must be maintained along the entire height of the stairs. The steps of steeply inclined stairs must be at least 150 mm away from the crane's metal structures.

226. Ladders for access from the floor to landing, repair sites and galleries for passage along the track should be located so as to exclude the possibility of trapping the personnel on them by a moving crane or its cabin, should be free and safe for personnel movement. It is not allowed to block up the specified stairs and store foreign objects on them.

227. On steeply inclined stairs, fences in the form of arcs should be arranged starting from a height of 2500 mm from the base of the stairs. The arcs should be spaced at least 800 mm apart and connected to each other by at least three longitudinal stripes.

228. The distance from the ladder to the arc must be at least 700 mm and no more than 800 mm with a radius of the arc from 350 mm to 400 mm. A guardrail in the form of arcs is not required if the staircase runs inside a lattice column with a cross section of no more than 900 x 900 mm or a tubular tower with a diameter of no more than 1000 mm.

229. The device of steeply inclined ladders over hatches is not allowed. If the height of the stairs is more than 10 m, platforms should be arranged every 6 - 8 m. When stairs are located inside a tubular tower, such platforms may not be arranged.

230. Inclined ladders located on cranes (with the exception of jib-type cranes) must be equipped on both sides with handrails with a height of at least 1100 mm relative to the steps and have flat metal steps with a width of at least 150 mm, excluding the possibility of sliding.

231. Ladders for entering platforms for servicing boom-type cranes must be stationary and (or) folding (retractable) with a handrail height at the entrance to the platform not less than 1500 mm.

232. The steps must be at least 320 mm wide with a step from 250 mm to 400 mm. The height from the floor surface or platform to the first step should be no more than 400 mm.

The size of the galleries is regulated by the Crane Rules. The width of the free passage through the gallery should be:
a) for cranes with a transmission drive - not less than 500 mm;
b) for cranes with a transmissionless or manual drive - at least 400 mm.
For the same cranes on galleries intended for the location of trolley wiring, the width of the passage between the railings and the devices supporting the trolleys, as well as current collectors, must be at least 400 mm.
The requirements of the Rules for cranes do not apply to the gallery of the overhead crane located on the side of the current supply, if the current supply to the electrical equipment of the trolley is made with a flexible cable. The cantilever holding the cable can traverse the entire width of the bridge gallery. The hatch for the exit to the bridge deck of such a crane must be equipped with an interlock that automatically relieves the voltage from the flexible cable when entering the bridge deck.
The distance from the end railing of the crane bridge to the protruding parts of the cargo trolley when it is in the extreme position is not regulated. This distance is sometimes taken to be less than 400 mm to increase the crane's service area. All these requirements also apply to gantry cranes and mobile jib cranes.
Overhead cranes controlled from the cab (except for single-girder and overhead cranes) must be equipped with cabins (platforms) for servicing the main trolley wires and current collectors, if they are located below the deck deck of the bridge. The hatch for entering from the bridge deck into this cabin must be equipped with a lid with a lock.
The dimensions of the cabin for servicing the main trolleys and their pantographs are not regulated and are usually taken 1000 x 1400 (PTO Komsomolsk-on-Amur plant) with a height of at least 1800 mm. It is not necessary to take the area of ​​the cabin less than 800 x 800 mm. The cabin must be fenced with a handrail of at least 1 m height with continuous filing along the bottom to a height of 100 mm. With a flexible current supply, the platforms are sometimes not arranged.
The crane bridge must be fenced on the four outer sides (along the perimeter) with a 1 m high handrail with a continuous fence at a height of at least 100 mm to prevent the fall of tools or parts during inspection and repair of crane mechanisms and electrical equipment.
Railings are not installed on the side of the cart on the galleries of the bridge and end beams.
In this regard, it is dangerous to be on the bridge of a crane made of lattice girders, in which the gallery floor is located at the level of the trolley rails, as it is possible to fall into the span between the trusses. Cases of people falling from a crane bridge have been reported exclusively on lattice girder cranes. In addition to the noted drawback (lack of proper fencing of galleries), on such cranes the passage along the floor is constrained due to the location of movement mechanisms on it, which also poses a danger to the service personnel. For cranes with box girders, the gallery deck is located below the level of the bogie rails, so passage through such galleries is not dangerous.
To prevent accidents on cranes of old structures, where the passage through the gallery is constrained, it is necessary to arrange bypass platforms at the locations of the electric motor and gearbox of the bridge movement mechanism or transitional bridges with handrails. Precautions should also be taken to ensure that the worker's feet do not slip on the deck when crossing.
The installation of handrails along the bridge from the side of the trolley causes difficulties in the maintenance and repair of the trolley mechanisms, since it is necessary to climb over the handrails.
The crane trolley must be fenced from the end sides with a 1 m high rail with a continuous filing at the bottom to a height of 100 mm. The railing on one of the longitudinal sides of the trolley should be installed if there is no gallery on that side along the crane bridge, for example, with a flexible current supply to the trolley.
For trolleys and end beams, it is allowed to reduce the height of the handrails if the dimensions of the building do not allow the installation of handrails with a height of 1 m.

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