TECHNICAL FIELD

The present disclosure relates to rapidly deployable structures. In some examples, the rapidly deployable structure may be civil engineering structure such as a bridge, dam, or roadblock, or a shield, or a shelter, or barrier, or vehicle, such as a boat.

BACKGROUND ART

In hostile environments, such as combat environments, it may be desirable to erect a structure such as a bridge, dam, roadblock, shelter, or barrier. Minimising the time taken to erect such structures is paramount to minimising detection by hostile forces/ reducing the opportunity for hostile forces to disrupt or prevent the deployment and/or utilisation of the structure. At present, such structures built, and inflated by, conventional means do not allow for: a desirably rapid deployment, suitable loadbearing capability, nor suitability to a hostile endowment .

It is an aim of the present disclosure to at least partially address the above problems.

SUMMARY OF THE INVENTION

According to an aspect of the disclosure there is provided a rapidly deployable structure comprising: one or more structural members configurable between a compressed configuration and an expanded configuration; at least one chemical inflator configured to rapidly expand the one or more structural members at least partially between the compressed configuration and the expanded configuration by chemical reaction; wherein when the one or more structural members are in the expanded configuration, the rapidly deployable structure is able to support at least its own weight.

Optionally the chemical inflator rapidly expands the one or more structural members by producing large volumes of gas.

Optionally the chemical inflator comprises one or more explosive compounds. Optionally the chemical inflator comprises an azide compound, which may be sodium azide.

Optionally the structure comprises an additional inflator configured to expand the one or more structural members, relatively slowly compared to the chemical inflator, at least partially between the compressed configuration and the expanded configuration by chemical reaction.

Optionally the rate of expansion by the additional inflator is controllable.

Optionally the additional inflator comprises an air pump.

Optionally the additional inflator is configured to expand the one or more structural members from the compressed configuration to a first intermediate configuration between the compressed configuration and the expanded configuration and/or from a second intermediate configuration to the expanded configuration.

Optionally the chemical inflator is configured to expand the one or more structural members from the first intermediate configuration and/or up to the second intermediate configuration.

Optionally the additional inflator is configured to be initiated in the event of a puncture or loss of pressure to maintain the one or more structures in the expanded configuration.

Optionally the one or more structural members comprises an exterior wall and the one or more structural members may comprise one or more interior walls.

Optionally the one or more interior walls define an internal cellular structure comprising at least two cells.

Optionally each cell comprises a respective chemical inflator. Optionally at least a subset of the one or more structural members is formed from a material resistant to puncture, abrasion and/or tearing.

Optionally the material is an aramid fibre or carbon fibre material.

Optionally the structure further comprises a reflective or retroreflective member.

Optionally the reflective or retroreflective member comprises a reflective or retroreflective material on the surface of the structure.

Optionally the reflective or retroreflective material comprises Mylar.

Optionally the reflective or retroreflective material comprise a metallic film.

Optionally the reflective or retroreflective comprises retroreflective glass micro beads.

Optionally the structure further comprises a radiation-absorbing member.

Optionally the reflective or retroreflective member is reflective to visible, IR, microwave radiation, and/or radio wave radiation.

Optionally the reflective or retroreflective member is configured to prevent the passage of EM data

Optionally the expanded one or more structural members are configured to be filled with a structure stabilising material, such as a rapidly expanding and setting foam, a hard setting material, such as concrete or epoxy.

Optionally the structure in the compressed configuration is contained, such that it can be airdropped or canister launched.

Optionally the structure comprises a self-destruction mechanism, configured to cause irreparable damage so as to render the structure unusable. Optionally the self-destruction mechanism comprises an explosive charge.

Optionally the self-destruction mechanism comprises a mechanism for rupturing the one or more structural members.

Optionally the structure is a civil engineering structure.

Optionally the structure is a bridge, dam, or roadblock.

Optionally the structure is a vehicle, which may be a boat.

Optionally the structure is a barrier or a shield.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the disclosure are described below by way of nonlimiting examples and with reference to the accompanying drawings, in which:

Fig. 1 shows first configuration of a first example structure;

Fig. 2 shows a second configuration of the first example structure;

Fig. 3 shows a third configuration of the first example structure;

Fig. 4 shows a fourth configuration of the first example structure;

Fig. 5 shows a variation of the first example structure;

Fig. 6 shows a first view of a second example structure;

Fig. 7 shows a second view of a second example structure;

Fig. 8 shows a third example structure; and

Fig. 9 shows a variation of the second example structure.

DETAILED DESCRIPTION

Figs. 1 to 4 show a first example rapidly deployable structure 1 according to the disclosure. The structure 1 in this example is a bridge is configured to fill a void to enable one or more vehicles to cross. However, the features described below are applicable to other structures, such as those described below. As shown, the structure comprises structural members 3 that are configurable between a compressed configuration shown in Fig. 1 and an expanded configuration shown in Fig. 4. The structural members 3 may inflatable, such that they are deflated in the compressed configuration and inflated in the expanded configuration. In the compressed configuration the structural members 3 may be slack and in the expanded configuration the structural members 3 may be under tension.

When the structural members 32 are in the expanded configuration, the rapidly deployable structure 1 should be able to support at least its own weight. In the present example, preferably, the structure 1 can support a vehicle weighing around 40 tonnes.

Preferably, in the compressed configuration the structural members are folded, rolled or otherwise arranged to reduce the space occupied thereby. In such a configuration, the structural members 3 may be retained in a casing 2, as shown in Fig. 1. The casing 2 is preferably openable to allow the structural members 3 to inflate, as shown in Figs. 2 to 4. However, the casing 2 may instead be reputable such that it ruptures when the structural members 3 inflate. The casing may be a canister, for example. The casing may be formed form a hard material, such as metal or plastic to protect the structural members 3.

Figs. 2 to 4 shows various stages of inflation of the structural members 3, namely a first intermediate configuration, a second intermediate configuration and an expanded configuration respectively. Between these configurations tension on the structural members 3 increases.

The structure 1 additionally comprises at least one chemical inflator 5. The chemical inflator 5 is configured to rapidly expand structural members 3 by chemical reaction. Preferably, the chemical inflator rapidly expands the one or more structural members by producing large volumes of gas. For example, the chemical inflator 5 may comprise one or more chemical compounds. An azide compound may be used, e.g. sodium azide. An additional accelerant may also be used. Alternative, rapidly reacting chemical compounds are possible including traditional explosives e.g. gunpowder, ANFO etc.

The structural members 3 may comprise one or more pressure release vents configured to vent gas when the pressure reaches a predefined threshold pressure. This may prevent damage to the structural members 3 in the event of overpressure from the chemical inflator 5. The pressure release vents may vent automatically at the threshold pressure, e.g. the vents may be forced open at or above the threshold pressure but remain closed below the threshold pressure.

The chemical inflator 4 is configured to at least partially expand the structural members 3 between the compressed configuration and the expanded configuration. The structure 1 may comprise an additional inflator 6 configured to expand the one or more structural members 3. The additional inflator 6 may use non-chemical means, such as an air pump, e.g. an electric pump. Compressed gas is also possible. The additional inflator 6 may expand the structural members 3 relatively slowly compared to the chemical inflator 5.

The additional inflator 6 may be integrated with of the structural members 3, as shown in Fig. 2. However, in alternative examples, the additional inflator may be a separate device that can be connected to (and optionally disconnected from) the structural members 3. In a specific example, the additional inflator 6 may be housed by a remote vehicle.

The additional inflator 6 may partially expand the structural members 3 between the compressed configuration and the expanded configuration in conjunction with the chemical inflator 3. For example, the additional inflator 6 may configured to expand the structural members 3 from the compressed configuration to the first intermediate configuration, instead of the chemical inflator 5. Alternatively or additionally, the additional inflator 6 may configured to expand the structural members 3 from the second intermediate configuration to the expanded configuration, instead of the chemical inflator 5.

The chemical inflator 5 may be configured to expand the structural members 3 after reaching the first intermediate configuration and/or before reaching the second intermediate configuration. Not using the chemical inflator 5 at either the start or end of inflation and using a slower additional inflator 6 instead may mitigate damage to the structural members 3 from the rapid expansion by the chemical inflator 5 around the compressed configuration when frictional forces may be high or around the expanded configuration when tensional stress may be high.

The first intermediate configuration may correspond to an inflation of between around 10% and 30%, e.g. around 20%. The second intermediate configuration may correspond to an inflation of between around 70% and 90%, e.g. round 80%. For example, the chemical inflator 5 may operate from around 20% to 80% inflation.

Additionally, the additional inflator 6 may be initiated in the event of a puncture or loss of pressure to the structure, in order to maintain the structural members 3 in the expanded configuration and load-bearing capability if required.

Preferably, both the chemical inflator 5 and the additional inflator 6 can be operated, e.g. initiated remotely.

Fig. 5 shows a cross section through an example structure 1. As shown in Fig. 5, the structural members 3 may comprise an exterior wall 3 A. Preferably, the wall 3 A is airtight. As shown in Fig. 5, the structural members 3 may comprise internal walls 3B. This internal walls 3B may define an internal cellular structure comprising cells 4.

The cellular structure may improve the strength of the structure, e.g. to enable it to be more heavily loaded. The cellular structure may increase the protection against damage, such as puncture. The cellular structure may enable control of the expansion of the structure. For example, cells may control gas flow from one cell to another. Alternatively, each cell may be individually inflatable, e.g. each cell comprised a respective chemical inflator 5.

The structural members 3 will preferably be formed from a material resistant to puncture, abrasion, and/or tearing, for example by projectiles such as incoming small arms rounds, or by contact with sharp or rough objects during or after expansion. The material may be an aramid fibre material, for example, such as Kevlar™ or Twaron™. Optionally the materials may be partially made from a carbon derived fibre such as carbon fibre. The external wall 3A may be formed from a different material to the internal walls 3B for example. Preferably, at least the external wall 3A is formed from a material resistant to puncture, abrasion and/or tearing. Preferably, at least the internals wall 3B closest to the external walls 3A, i.e. forming a first layer of cells 4, are formed from a material resistant to puncture, abrasion and/or tearing. This may provide additional protection to the structure 1. In an example, the structure 1 may comprise a self-destruction mechanism, configured to cause irreparable damaged to the structure 1 so as to render the structure unusable. The self-destruction mechanism may comprise an explosive charge. The self-destruction mechanism comprises a mechanism for rupturing one or more of the structural members 3.

After deployment, the expanded structural members 3 may be configured to be filled with a liquid or foam material which cures to provide structural stability without the need to maintain air pressure. For example, structure stabilising material may comprise a rapidly expanding and setting foam. This foam may be made from polyurethane. Alternatively, the structure stabilising material comprises a hard setting material such as concrete or epoxy. Accordingly, the structure 1 may be strengthened further.

Figs. 6 and 7 show a second example rapidly deployable structure 10 according to the disclosure. The structure 10 in this example is a shield or barrier. The shield is configured to protect an asset as described further below. However, the features described below are applicable to other structures, such as those described above or below.

The structure 10 may comprise a reflective or retroreflective member 7. The reflective or retroreflective member 7 may comprise a reflective or retroreflective material on the external surface of the structure 10 (e.g. external wall 3 A). Alternatively or additionally, a reflective or retroreflective material may be provided on one or more internal surfaces of the structure 10 (e.g. internal walls 3B). A plurality of layers of reflective or retroreflective material may be provided, e.g. incrementally deeper within the structure 10. The reflective or retroreflective material may comprise Mylar, for example. The reflective or retroreflective material may comprise a reflective metallic film, for example. The reflective or retroreflective may comprise retroreflective glass micro beads, for example.

Depending on the intended use of the reflective or retroreflective member, the reflective or retroreflective member may be reflective to visible, IR, microwave radiation, and/or radio wave radiation or a combination thereof. The reflective or retroreflective member may be configured to prevent the passage of electromagnetic data, as shown in Fig. 6.

In other examples, the structure 10 may comprise a radiation-absorbing member (which may be arranged in a similar fashion to the reflective or retroreflective member 7). The radiation absorbing member may comprise a radiation-absorbing material on the external surface of the structure 10 (e.g. external wall 3 A). Alternatively or additionally, a radiation-absorbing material may be provided on one or more internal surfaces of the structure 10 (e.g. internal walls 3B). A plurality of layers of radiation-absorbing material may be provided, e.g. incrementally deeper within the structure 10. The radiationabsorbing material may be, for example, a Salisbury Screen type of structure or a frequency-selective surface.

Depending on the intended use of the radiation-absorbing member, the radiation-absorbing member may absorb visible, IR, microwave radiation, and/or radio wave radiation or a combination thereof.

The use of a radiation-absorbing member may reduce or remove the likelihood of the structure 10 being visible, either to visual or electromagnetic detection (e.g. radar).

The radiation-absorbing member may be configured to prevent the passage of electromagnetic data.

The radiation-absorbing member may be configured to permit a selected frequency or range of frequencies to pass through the member. For example, if the structure is deployed around a radiation transmitter, receiver or transceiver (e.g. a radio antenna or radar system).

The reflective or retroreflective member 7 and the radiation-absorbing member described above may both be used in a single structure.

Reflective and retroreflective properties may be used to locate a structure, e.g. by illuminating with a laser, or using a radar.

Fig. 9 shows a variation of the second example structure 10. In this example, the structure 10 is not a standalone structure, as shown in Figs. 6 and 7, but may be attached to, or integrated with, another structure 30 or device. As shown in Fig. 9, the other structure 30 may be a vehicle. In another example, a device may be an item of apparel or pack worn by a person. Fig. 8 shows a third example structure 20. The thirds example structure 20 is a vehicle, namely a boat. Although not shown, the structure may comprise means for propelling the vehicle such as a motor.

It should be understood that variations of the above described examples are possible in light of the above teachings, without departing from the spirit or scope of the disclosure as defined by the claims.