GB2220390A

GB2220390A - Periscope system

Info

Publication number: GB2220390A
Application number: GB8915072A
Authority: GB
Inventors: Barr Stroud Limited; Stanley John Pratt
Original assignee: Thales Optronics Ltd
Current assignee: Thales Optronics Ltd
Priority date: 1988-07-07
Filing date: 1989-06-30
Publication date: 1990-01-10
Anticipated expiration: 2009-06-30
Also published as: GB8816206D0; GB8915072D0; GB2220390B

Abstract

A submarine mast system 10 having a mast 11 which penetrates the hull 8 is supported by an integrated tubular sub-assembly 15 connected to the submarine superstructure 9 at its upper end by a set of three similar equi-angularly spaced radially-extending linkage devices 16 and at its lower end to the hull 8 by an annular device 17. The mast 11 is rotatable in bearings 18 secured to the sub-assembly 15 which is of sufficiently high stiffness to maintain the bearings 18 in alignment to enable relatively free hoisting and rotary movements of the mast 11. The annular device 17 includes a resiliently yieldable member to isolate the sub-assembly 15 from strains experienced by the superstructure 9 when the system 10 is in use. <IMAGE>

Description

PERISCOPE SYSTEM This invention relates to submarine mast systems.

In known forms of submarine mast systems the mast, which may be in the form of a conventional optical periscope or a more modern opto-electronic tube, penetrates the hull of the submarine and extends upwardly and outwardly of the hull into a fin or sail superstructure which at its top is apertured to permit the mast to be hoisted bodily or telescopically to enable operation of observation devices mounted at the top of the mast. The length of the mast located within the superstructure is considerable, e.g. 15 to 20 feet and is supported at intervals by at least three bearings intended to facilitate both hoisting and rotary movements of the mast, the latter being required to change the field of view azimuthally of the observation devices.The bearings are secured to the superstructure and within specified tolerances are maintained in alignment but as the submarine fin or sail is subjected in service to strains due to physical environmental forces such strains are transmitted to the bearings which become at least temporarily misaligned so that the hoisting and rotary drive mechanisms for the mast fail to operate satisfactorily which impedes efficient use of the mast. Typical environmental forces are shock loading and vibration imposed by vortex shedding forces and wave slap.

Also, known arrangements for supporting the hoisting mechanisms within the fin or sail subject these mechanisms to similar strains with consequential alignment loss which in turn adversely affects operation of the mast.

It is an object of the present invention to provide a new and improved form of submarine mast system.

According to the present invention there is provided a submarine mast system comprising an integrated tubular sub-assembly carrying a submarine mast and hoisting mechanism, the mast being rotatable in bearings secured to the sub-assembly which is of sufficiently high stiffness to maintain the bearings in alignment to enable relatively free hoisting and rotary movements of the mast, the sub-assembly having lower connection means at its lower end for connecting to the submarine hull and upper connection means at its upper end for connecting to the submarine fin superstructure, said lower connection means comprising a resiliently yieldable member to isolate the sub-assembly from strains experienced by the superstructure when the system is in use.

Preferably the upper connection means comprises three similar linkage devices equi-angularly spaced extending outwardly of the said upper end of the sub-assembly. Each linkage device may extend radially outwardly or may extend in a downwards and outwards direction. Each said linkage device may also comprise a resiliently yieldable member.

Preferably the lower connection means comprises an annular device including a plurality of bolt arrangements for securing the device to the submarine hull. The annular device may be of sandwich structure incorporating the resiliently yieldable member bonded therein. Additionally or alternatively each said bolt arrangement may comprise a said resiliently yieldable member.

Preferably the tubular sub-assembly comprises a plurality of axially extending radially protruding webs to impart stiffness to the sub-assembly.

Preferably the sub-assembly comprises a plurality of axially conjoined segments including a lowermost segment incorporating a lowermost mast bearing, an uppermost segment incorporating an uppermost mast bearing. An intermediate mast bearing may be incorporated either in an intermediate sub-assembly segment or in either the uppermost or lowermost segment.

Embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings, in which: Fig. 1 schematically illustrates part of a submarine incorporating a submarine mast system according to the present invention; Fig. 2 illustrates part of the Fig. 1 mast system in more detail; Fig. 3 shows a detail of Fig. 2 to a larger scale; Fig. 4 illustrates another detail of Fig. 2 in more detail; Fig. 5 is a sectional view taken on the line A-A in Fig. 2; Fig. 6 illustrates a further detail of Fig. 2 in more detail; Fig. 7 illustrates a component of the Fig. 6 detail.

Fig. 8 illustrates an alternative form of the mast system; Fig. 9 is a sectional view taken on the line B-B in Fig. 8; Fig. 10 shows a detail of the Fig. 8 system to a larger scale; and Fig. 11 shows part of Fig. 10 to a larger scale.

As is shown in Fig. 1 a submarine includes a pressure hull 8 on an upper part of which is secured a superstructure 9 for supporting one or more mast systems 10, lOA,lOB,lOC at least one of which (10) includes a mast 11 which penetrates the hull 8 and which is adapted for both axial movement (hoisting) and rotary movement so that observation devices (not shown) mounted at the top end of the mast 11 can be deployed as required by an operator. To provide streamlining the superstructure 9 is encased in a covering 12 but even with such covering 12 the superstructure 9 is, in use, subjected to various environmental physical forces such as shock loading and vibrational loading as imposed by vortex shedding forces and wave slap which tends to be transmitted throughout the structure by members 12 and 9 or via masts lOA, lOB, lOC if any one or all of these are raised.

In accordance with the present invention the mast system 10 is provided with an integrated tubular sub-assembly 15, best shown in Fig. 2 which carries both the mast 11 and its hoisting mechanism and which is connected to the superstructure 9 at its upper end by a set of three similar equi-angularly spaced radially extending linkage devices 16 and to the hull 8 at its lower end by an annular device 17.

As is more clearly shown in Fig. 2 the sub-assembly 15 is composed of a plurality of axially conjoined segments 15A,15B,15C,15D and 15E of which segment 15A, the uppermost segment, houses an uppermost mast bearing 18A; segment 15E, the lower most segment, houses a lowermost mast bearing 18C; and segment 15C, the intermediate or middle segment, houses a middle mast bearing 18B. The adjoining segments 15A to 15E are conjoined in a releasable manner by a plurality of periphally extending bolts so that each of the bearings 18A to 18C can be replaced and also to facilitate initial alignment of these bearings so that the mast 11 is relatively freely rotatable and axially movable.The cross-sectional view of the sub-assembly 15 shown in Fig. 5 illustrates that segment 15B, like the other segments, comprises a central tube 19 exteriorly provided with four axially extending radially protruding webs 20 terminating at each end, by welded connection, at flanges 21 through which the segment-interconnecting bolts pass. Tube 19 is provided with windows 22 to lighten the weight of the sub-assembly 15 without detriment to stiffness particularly when made of metal although sub-assembly 15 could be made of any lightweight material, for example, glass or carbon fibre reinforced plastics.

As is also shown in Fig. 5 certain flanges 21 are locally cut-away to accommodate diametrically opposed pairs of hydraulic rams 24A,24B of which only one is shown in Fig. 2 in the interest of clarity. The rams 24A,24B function together as a hoisting mechanism for the mast 11 being connected inwardly of hull 8 to a mast lifting yoke (not shown) and are maintained in axial alignment with the mast 11 by being secured to the segment 15B at 25 and at the segment 15E.

The sub-assembly 15 at its upper end is connected to the superstructure 9 by three similar equi-angularly spaced linkage devices 26 one of which is shown in detail in Fig. 3. Each device 26 comprises a turn-buckle 28 connected to pin-joint arrangements 29,30 at its respective ends. Arrangement 30 is non-yieldably secured to an eye 31 (Fig. 4) formed in the uppermost flange of segment 15B whereas arrangement 29 is resiliently yieldably secured to superstructure 9 by means of an elastomeric member 29A which conveniently is bonded on its opposite faces, typically by Metalstik (trademark). The turn-buckles 28 enable initial setting of the mast 11.

At its lower end the sub-assembly 15 is connected to hull 8 by segment 15E which is an annular device bolted, by perimetrically arranged bolts 35, as shown in Fig. 6, being interfaced by a sealing gasket 36 (shown in Fig.

7) including a raised sealing bead 36A. Gasket 36 includes a central aperture 37 for the mast 11 and diametrically disposed apertures 38A,38B for the rams 24A,24B all within the bead 36A. Each bolt 35 has a castle-type lock nut seated onto a resilientlyyieldable washer 39 which may be of a Belleville type or a metal elastomer composite type or simply an elastomer type having regard to the fact that the degree of movement experienced at the lower end of the sub-assembly 15 is substantially less than that at the upper end.

It will be appreciated that by virtue of the resiliently yieldable components 29A,39 the sub-assembly 15 is essentially isolated from strains experienced by the superstructure 9 so that alignment of the bearings 18A to 18C is improved in comparison with previous arrangements thereby leading to improved utilisation of the mast 11 and its observation devices. Additionally because of the presence of components 29A,39 and the preferred materials from which they are made an inherent damping effect is introduced to protect the sub-assembly 15 from the adverse effects of environmental shock loadings which cannot be avoided during service use of the submarine.The sub-assembly 15 affords greater ease of installation and maintenance (including removal) of the mast 11 or its bearings 18A to 18C, particularly bearing 18B which can be floated and pinned for alignment after the mast 11 has been inserted.

The alternative mast system 10' shown in Fig. 8 is generally similar to the system 10 of Fig. 1 but differs in various details. System 10' includes an integrated sub-assembly 15' composed of only three axially conjoined segments. The uppermost segment 15A which houses the uppermost mast bearing 18A is connected by three equi-angularly spaced linkage devices 26' to the superstructure 9, each device 26' extending outwardly and downwardly from sub assembly 15' at an angle of about 450 to the horizontal. Devices 26' are free of elastomeric or other resiliently yieldable materials and are inclined as described to reduce the amplitude of the vibrational forces imposed by the superstructure 9 on the sub-assembly 15', and amplitudes being approximately proportional to the third power of the height of the connecting point of devices 26' above the hull 8.

Segment 15C in this embodiment is omitted from sub-assembly 15' and the middle bearing 18B is housed at the upper end of the lowermost segment 15D which at its lowermost end incorporates the lowermost or hull bearing 18C at annular device 17' which is shown in greater detail in Fig. 10. In Figs. 10 and 11 the hull aperture is provided by a raised collar 41 to which annular device 17' in the form of a sandwich construction of upper and lower metal plates 42A, 42B bonded to an intermediate pressure sealing elastomeric layer 43 is secured by a plurality of bolts each penetrating a toe clamp element 44 which at its upper end overhangs a flange of the carrier 45 for the lowermost bearing 18C.

Element 42A is joined to carrier 45 by a plurality of bolts and beaded gaskets or O-ring seals are provided to effect pressure sealed boundaries at the interfaces of device 17' and components 41 and 45. Elements 44, which are distributed around the periphery of annular member 17' provide limited clearance for limited pivotal movements of member 17' when the system 10' is subjected to in service loadings. Elastomeric pressure sealing and load bearing layer 43 is inhibited against excess bulging radially outwardly by the elements 44 and against any bulging radially inwardly by a metal ring 43A screwed to plate 42A.

As is shown in Fig. 9 the assembly 15' and the collar 41 in this embodiment are preferably circular in cross-section which simplifies fabrication in comparison to the oval section of Fig. 7. As previously assembly 15' is provided with outwardly protruding flanges 20' but as shown in Fig. 9 these are not radial.

Claims

1. A submarine mast system comprising an integrated tubular sub-assembly carrying a submarine mast and hoisting mechanism, the mast being rotatable in bearings secured to the sub-assembly which is of sufficiently high stiffness to maintain the bearings in alignment to enable relatively free hoisting and rotary movements of the mast, the sub-assembly having lower connection means at its lower end for connecting to the submarine hull and upper connection means at its upper end for connecting to the submarine fin superstructure, said lower connection means comprising a resiliently yieldable member to isolate the sub-assembly from strains experienced by the superstructure when the system is in use.

2. A mast system as claimed in claim 1, wherein the upper connection means comprises three similar linkage devices equi-angularly spaced extending outwardly of the said upper end of the sub-assembly.

3. A mast system as claimed in claim 2, wherein each linkage device extends radially outwardly.

4. A mast system as claimed in claim 2, wherein each linkage device extends in a downwards and outwards direction.

5. A mast system as claimed in any one of claims 2-4, wherein each said linkage device also comprises a resiliently yieldable member.

6. A mast system as claimed in any preceding claim wherein the lower connection means comprises an annular device including a plurality of bolt arrangements for securing the device to the submarine hull.

7. A mast system as claimed in claim 6, wherein the annular device is of sandwich structure incorporating the resiliently yieldable member bonded therein.

8. A mast structure as claimed in claim 6 or claim 7, wherein each said bolt arrangement comprises a said resiliently yieidable member.

9. A mast structure as claimed in any preceding claim, wherein the tubular sub-assembly comprises a plurality of axially extending radially protruding webs to impart stiffness to the sub-assembly.

10. A mast structure as claimed in any preceding claim, wherein the sub-assembly comprises a plurality of axially conjoined segments including a lowermost segment incorporating a lowermost mast bearing, and an uppermost segment incorporating an uppermost mast bearing.

11. A mast structure as claimed in claim 10, wherein An intermediate mast bearing is incorporated either in an intermediate sub-assembly segment or in either the uppermost or lowermost segments.