Today, containers are largely used for breaks by the crew or construction sites. These containers are especially adaptec for the purpose and each have at least one door opening foi passage of the crew.

In e. g. urban areas where the surrounding space is often confined, the containers are often stacked on top of eacl other. Access to the overlying containers is then obtained bi means of a staircase with a landing disposed opposite a doo : opening.

Such a staircase is known from the patent document DE 195 0 : 648 C1. In this case, the landing is supported by horizontally projecting crossbeams each firmly connected to an upper par' of a vertical column. The variable load on the landing plu the dead load of this landing stress the column with both vertical downward force and a bending moment.

This combined force load is unfavourable to a column which which if occasion should arise, could collapse and thereb make the whole construction collapse with the result of peopl standing on the landing getting seriously hurt.

Therefore, the columns of this known staircase must be ver strong to be able to live up to the safety required by th authorities. The structure will therefore be heavy and costly and to this should be added that the staircase is als relatively difficult and time-consuming to mount and demount among other things because the columns have to be underbuil if the base is not sufficiently solid.

In one aspect of the invention a staircase of the kind mentioned in the opening paragraph is provided that has a light and inexpensive structure.

In a second aspect of the invention a staircase of the kind mentioned in the opening paragraph is provided that in static respect is expedient.

In a third aspect of the invention a staircase of the kind mentioned in the opening paragraph is provided that can be mounted and demounted quickly and easily.

According to the invention, the landing of the staircase is supported by vertical support bars hanging down along the side of the container.

As the support bars easily can absorb bending moments without collapsing, an optimally favourable, static structure is obtained. This means that the staircase will be light and inexpensive because its support bars now can be constructed to have far smaller dimensions than the columns of prior art.

Furthermore, the staircase will be quick and easy to mount and demount as the need for founding separate foundations no longer is present. The vertical loads are absorbed via the containers that normally have a large bearing face and that therefore do not require underbuilding even in cases where the base is not very solid.

Each support bar can be detachably hung on the container by means of an angle iron attached at the top of the bar and having a vertically projecting tab for supporting against the top face of the container.

Therefore, the support bars can be mounted quickly and easily on the container by merely hanging them on its top face by

means of the angle iron, and they can be taken down again just as quickly and easily.

It is important that the projecting tabs of the support bars do not let go of their abutment with the top face of the container under the influence of extraneous forces that could push the landing and thereby its load-bearing support bars away from the side of the container. For this could mean that the landing would fall down and that persons standing on the landing thereby could get hurt.

To avoid this risk, the projecting tabs of the support bars can be screwed onto the container but in an advantageous embodiment, each support bar can be retained in its position along the side of the container by a strap connected to the tab at one end and to an anchor that can absorb tensile loads in the strap at the other end.

Said anchor can be a part of the container. Alternatively, the anchor can be a lower part of the support bar and/or the landing, the strap then being passed round the container.

Thereby, the advantage is obtained in that both the upper- and the lower ends of the support bar are kept in position along the side of the container.

In an advantageous embodiment a tension device can be part of each strap for tightening the strap up to thereby be able to keep the support bar tight and thereby securely in against the side of the container.

As mentioned, the normally horizontal floor of the landing is supported by the vertical support bars. The dead load of the landing plus the variable load from persons and goods on the floor can expediently be transmitted to the support bars via horizontally cantilevered crossbeams each moment-resistantly connected to a lower part of a support bar.

To be able to mount and demount the staircase according to the invention quickly and easily in accordance with the task set, an angle iron having opposite tabs for detachably receiving two U-shaped longitudinal beams with opposite tabs can be attached at either end of a crossbeam.

The floor of the landing can then be formed of a number of e. g. box-shaped elements inserted between the webs of the longitudinal beams and fastened between these by means of screws or similar means in the outermost angle irons.

By means of the above structure a simple, elegant solution of the task of mounting and demounting the staircase quickly and easily is obtained.

The support bars can be telescopic so that they can be adapted to the length of containers of different heights and the longitudinal beams can also be telescopic to thereby be able to build landings of different lengths.

The invention will be explained in greater details below, describing an only exemplary embodiment with reference to the drawing, in which Fig. 1 is a perspective view of a staircase according to the invention mounted on a container standing on top of another container, Fig. 2 is a sectional view taken along the line II-II of fig. 1, and Fig. 3 is on a larger scale a fractional sectional view taken along the line III-III of fig. 2.

Figs. 1-3 show a staircase designated generally by the reference numeral 1 and leading up to an upper container 3

standing on top of a lower container 4 from the ground level 2.

In the following the containers are assumed to be arranged as accommodation space for the crew on a construction site.

Access to these rooms is obtained via a door 5 in the side of the upper container 3 and via a door 6 in the end of the lower container 4.

In the case shown, the staircase is composed of a single flight of stairs 7 and a landing 8. The stair flight is extending obliquely upwards from ground level to the landing disposed opposite the door 5 in the upper container 3. A handrail is extending along the outer side of both the stair flight and the landing.

The above arrangement is only to be taken as an example.

Within the scope of the invention the staircase can thus have several stair flights and several landings disposed opposite each of their of several crew containers standing on top of each other. Furthermore, the landings can have any suitable length and for example be extending past several doors in the same container or past doors in containers disposed on the same level in a line after each other.

The landing 8 is mainly supported by vertical support bars 9 hung on the top face 11 of the upper container 3. In the case shown, the support bars furthermore each have a lower angle iron 12 for gripping under the lower face 13 of the container.

Each support bar consists of lower and upper bar parts 12'and 12''that can be displaced in relation to each other and locked together by bolts (not shown) in cross holes 14. In this way the support bars can be telescopically adapted to the actual height of a container.

Between the containers, a spacer 15 is disposed for keeping the containers at a vertical distance from each other to thereby allow e. g. the forks of a fork-lift truck (not shown) to get in under the containers when they are to be put in position or moved.

Each support bar is clamped in against the side of the upper container by means of a strap 16 passed around the container and attached to the upper-and lower angle irons 10 and 12 respectively at the ends. The strap is tightened by means of a known tension roller 17 located on the upper bar part 12''of the support bar and/or the upper angle iron 10.

Instead of the upper angle iron for mounting of the support bar, this bar can alternatively hang directly in the strap (not shown).

At the bottom of each support bar, a mainly horizontal crossbeam 18 is moment-resistantly cantilevered and is provided with an upwardly projecting angle iron 19 at either end, the tab 20 of said angle iron facing the tab on the opposite angle iron.

On top of the crossbeam 18 a U-shaped longitudinal beam 21 is detachably inserted in each angle iron 19, the tabs 22 of which beam 21 are facing the opposite longitudinal beam 21.

The two longitudinal beams are bridging the gap between two adjacent crossbeams.

The longitudinal beams 21 consist of first-and second bar parts 21'and 21''displaceable in relation to each other to thereby allow construction of landings of different lengths.

A number of box-shaped floor elements 23 are fastened between the webs 24 of the longitudinal beams 24 by means of screws 25 in this case in the outermost angle iron 19.

The dead load of the landing and the variable load from persons and goods on the landing stress the support bars to both pull and bending. Contrary to the columns conventionally used for supporting a landing, the support bars according to the invention can however easily withstand this form of load without collapsing.

Therefore, relatively light and inexpensive tensional bars can advantageously be used for supporting the landing.

The structure according to the invention furthermore has the considerable advantage of the landing being quick and easy to assemble and disassemble.

It has thus proven that a staircase according to the invention having one flight of stairs and one landing easily can be mounted by one assembler in about 15 min. without use of a crane vehicle.

Another advantage is that the landing takes up very little space in disassembled state, and that it therefore can be transported back and forth between storage and construction site or from one construction site to another at a relatively low cost.