GB2090893A

GB2090893A - Building pontoon bridges

Info

Publication number: GB2090893A
Application number: GB8135322A
Authority: GB
Original assignee: Salzgitter AG
Current assignee: Salzgitter AG
Priority date: 1980-11-25
Filing date: 1981-11-24
Publication date: 1982-07-21
Also published as: GB2090893B; DE3044267A1; DE3044267C2

Abstract

A floating pontoon (1) having supports (9) for an incoming bridge section (3) is provided with an auxiliary retractable support (2) which is used to receive the incoming section (3), or to offload an outgoing section, and which is located centrally to reduce the danger of tilting the pontoon. The auxiliary support (2) has sliding or rolling elements (10) for supporting and allowing displacement of the bridge section (3) and has raising and lowering means (11) by means of which the support (2) may be lowered beneath the support surface (6, 9) of the pontoon (1). An incoming bridge section (1) engaging the auxiliary support (2) is located by a retractable guide/clamp 12 and by fixed guides 13. <IMAGE>

Description

SPECIFICATION Apparatus on pontoons for laying bridge sections and/or track carriers The invention relates to an apparatus on pontoons for laying bridge sections and/or track carriers on floating bodies which are spaced apart and disposed parallel one with the other.

During the laying of floating bridges, it is known to deposit bridge sections preferably onto two pontoons which are spaced apart and disposed parallel one with the other, whereby the bridge sections, which are thus manoeuvrable, are joined together to form a bridge or are used as ferries for crossing purposes.

With the known apparatus, numerous problems arise when laying the bridge sections on the pontoons, which are already floating in the water, since the bridge sections have to be laid accurately and fixed to the supporting points provided therefore on the pontoons. This is even more difficult to carry out if, for example, when there is a strong current, the pontoons have to be kept in the water transversely to the laying direction of a stationary laying system on the bank so as to prevent a relative movement between the laying apparatus and the pontoons. Because this is practically impossible to effect in practice, it is extremely difficult to guide a bridge section accurately onto the supporting points of the pontoon both in the longitudinal and in the transverse direction relative to the longitudinal axis of the pontoon.During this manoeuvre, the men working on the pontoon are in great danger because they are responsible for catching the guided bridge section e.g. by means of grappling hooks, and to secure it provisionally at the required location on the pontoon.

However, an incomparably greater danger lies in the fact that the bridge section cannot be deposited upon the pontoons horizontally to the water surface from the bank, because the difference in height between the water surface and the bank region is very variable, and the bridge section therefore always comes to rest on the pontoon at an angle of inclination. This means that, in each case, the pontoon tilts dangerously at the end which is remote from the bank, and transverse forces, acting in the direction of the bank are produced which have to be compensated, e.g. by grappling hooks on the pontoon. The men in the workforce who are required on the deck of the pontoon are, as a consequence, in extreme danger and may fall overboard into the water.This above-described situation is particularly dangerous when the bridge section is removed from the pontoon, since grappling hooks are necessary therefore which are then under considerable tension.

The object of the present invention is to eliminate the above-described disadvantages when bridge sections are laid on pontoons and, in addition, to shorten the laying time and also to automate the depositing, fixing and locking work between the bridge section and the pontoon.

According to the present invention there is provided an apparatus on pontoons for laying bridge sections and/or track carriers on floating bodies which are spaced apart and disposed parallel one with the other wherein the pontoons are each provided, substantially in the centre, with at least one auxiliary support carrier which extends parallel with the longitudinal axis and protrudes beyond the pontoon surface and with means for the central guidance of a bridge section, which is slidable in the transverse direction relative to the longitudinal axis of the pontoon, wherein the auxiliary support carriers may be lowered beneath the pontoon surface, or beneath the plane of the main supports of the pontoon.

Two or more pontoons having these features permit the simple transfer, alignment and support of any bridge section in a short time and without manual assistance from men working on the pontoon who can now concentrate exclusively on the necessary nautical work involved.

The present invention will be described further by way of example, with reference to the accompanying drawings, in which:- Fig. 1 shows an auxiliary support carrier, which has been raised above the pontoon surface and has a bridge section resting thereon, viewed in the direction of the longitudinal axis of the pontoon; Fig. 2 is a view showing the carrier of Fig. 1, viewed transversely to the longitudinal axis of the pontoon: Fig. 3 shows an arrangement of two auxiliary support carriers with means for restricting the transverse advance of the bridge section, viewed in the direction of the longitudinal axis of the pontoon; Fig. 4 is the view showing the arrangement of Fig. 3, viewed transversely to the longitudinal axis of the pontoon; Fig. 5 shows a bridge section resting on auxiliary support carriers; and Fig. 6 shows a bridge section which has been lowered onto the main pontoon supports.

Fig. 1 shows a pontoon 1 with an auxiliary support carrier 2 in the extended position. A bridge section 3 rests on the auxiliary support carrier 2 and is pushed from the bank onto the pontoon 1 in the direction of the arrow 4 at an angle of inclination a. Because the auxiliary support carrier 2 absorbs the load in the central region of the pontoon, the otherwise inevitable tilting of the pontoon 1 at an angle P relative to the waterline 1 7 is avoided.Only when the bridge section 3 rests on a further auxiliary support carrier (not shown) of an adjacent pontoon and when the lower flange 5 of the bridge section 3 has adopted a substantially parallel position relative to the pontoon surface 6, is the bridge section 3 brought to rest on the pontoon surface 6 by lowering the auxiliary support carrier 2 into the lower position 71 by means of the suspension means 7. The lower flanges 5 of the track carriers 8 are supported on the fully loadable main supports 9.

In a further preferred embodiment, the auxiliary support carrier 2 is provided with sliding or rolling elements 10 in order to reduce the friction between the bridge section 3, which moves in the direction of the arrow 4, and the pontoon 1, and dangerous transverse forces acting upon the pontoon are therefore avoided. The raising and lowering movements of the auxiliary support carrier 2 are effected pneumatically or hydraulically by means of a piston-cylinder unit 11.

In the view shown in Fig. 2, an insertion clamp 12 is shown, which may also be lowered beneath the pontoon surface 6. However, this clamp 12 may alternatively be connected to the auxiliary support carrier 2. The insertion clamp 12 serves to guide the track carriers 8 of the bridge section 3, which initially is only lowered in an imprecise manner towards the auxiliary support carriers 2 so that the lower flanges 5 of the bridge section 3 are deposited accurately onto the rolling elements 10 as the bridge section 3 is further lowered. During subsequent lowering of the auxiliary support carrier 2, the bridge section 3 is accurately positioned onto the main Supports 9 of the pontoon 1.Shortly before the bridge section S is lowered onto the main supports 9, any slight deviations from the correct angle between the longitudinal axes of the bridge and pontoon are corrected by the chamfered insert-pieces 13 which are disposed laterally on to the pontoon 1.

Fig. 3 shows a further embodiment in which two auxiliary support carriers 2 are supported on a pontoon 1. This arrangement is particularly advantageous if the track carriers 8 of the bridge section 3 are to be laid separately, and at the same time an advantageous mounting of the lowerable insertion clamp 12 is ensured thereby.

In addition, the insertion clamp 12 may simultaneously serve to restrict the advance of the bridge section 3 which is to slide transversely to the longitudinal axis of the pontoon 1. As can be seen from Figs. 3 and 4, stops 14 are disposed on the lower flange 5 for this purpose, these stops 14 being able to slide in the direction of the arrow 4 as far as the insertion clamp 12 and restricting the further displacement of the bridge section 3 relative to the pontoon 1. The lateral distance between the pontoons 1 and the supporting points 15 provided on the bridge section 3 is kept accurate hereby, and the transverse forces which act upon the pontoon 1 are absorbed during the lowering and removal of the bridge section 3. The displaceability of the bridge section 3 on the auxiliary support carriers 2 is particularly advantageous.For example, if a bridge is being laid from a high sloping bank, the pontoon 1 may travel over the rollers 10 of the auxiliary support carrier 2, beneath the bridge section 3, to such an extent that at the end remote from the bank that the endpiece protruding beyond the pontoon 1 is kept short so that there is no possibility of this end piunging into the water.

Fig. 5 shows a compietely laid bridge section 3 which still rests on the auxiliary support carriers 2.

From this position, the bridge section 3 is lowered onto the main supports 9 of the pontoon 1, as shown in Fig. 6. Only then is the bridge or ferry capable of being loaded and may be used for its intended purposes.

To lock the bridge section 3 to the pontoon 1, the insert-pieces 1 3 are provided with locking claws 1 6 which -- actuated hydraulically or manually - engage around the lower flange 5 and secure it to the pontoon 1. As can be seen from Fig. 3, the locking claws 1 6 are pivoted by means of a piston-cylinder unit 18, after the track carrier 8 has been lowered, whereby the closed locking claws 1 6, fixedly anchor the lower flange 5 of the track carrier 8 to the pontoon 1.

A pontoon having these features -- depending on whether it is provided with, for example, a pneumatic or hydraulic control system known per se - permits the partiaily automatic or the fully automatic laying and connecting of bridge section 3 to the supporting pontoon 1.

Claims

1. An apparatus on pontoons for laying bridge sections and/or track carriers on floating bodies which are spaced apart and disposed parallel one with the other, wherein the pontoons are each provided, substantially in the centre, with at least one auxiliary support carrier which extends parallel with the longitudinal axis and protrudes beyond the pontoon surface, and with means for the central guidance of a bridge section, which is slidable in the transverse direction relative to the longitudinal axis of the pontoon, and wherein the auxiliary support carriers may be lowered beneath the pontoon surface, or beneath the plane of the main supports of the pontoon.

2. An apparatus on pontoons as claimed in claim 1, wherein the auxiliary support carriers are provided with sliding or rolling elements for accommodating bridge parts.

3. An apparatus on pontoons as claimed in claims 1 and 2, wherein at least one pistoncylinder unit which is hydraulically or pneumatically actuable, is disposed on suspension means for raising and lowering the auxiliary support carrier.

4. An apparatus on pontoons as claimed in claims 1 to 3, wherein the means for the central guidance of the bridge section comprises an insert clamp which may be raised above the pontoon surface, corresponds to the contours of the bridge cross-section, and may be lowered into the pontoon.

5. An apparatus on pontoons as claimed in one or more of the preceding claims, wherein chamfered insert-pieces are provided adjacent to the main supports and are disposed rigidly on the pontoon.

6. An apparatus as claimed in claim 5, wherein the insert-pieces have associated locking claws, by means of which the lower flanges of the bridge section or the lower flanges of the track carriers may be connected to the pontoon.

7. An apparatus as claimed in claim 6, wherein the locking claw is actuable pneumatically or hydraulically by means of a piston-cylinder unit.

8. An apparatus as claimed in one or more of the preceding claims, wherein stops are disposed on the lower flange.

9. An apparatus on pontoons, for laying bridge sections and/or track carriers on floating bodies which are spaced apart and disposed parallel one with the other substantially as herein described with reference to and as illustrated in the accompanying drawings.