WO2022243706A1

WO2022243706A1 - Ventilation devices, systems and methods for train depots

Info

Publication number: WO2022243706A1
Application number: PCT/GB2022/051288
Authority: WO
Inventors: Stephen Michael TAYLOR; Elizabeth Taylor
Original assignee: Emeg Group Limited
Priority date: 2021-05-21
Filing date: 2022-05-20
Publication date: 2022-11-24
Also published as: GB202107335D0; GB2608984A

Abstract

Devices (1), systems (10) and method for ventilating train depots are disclosed in which a hood (5) is provided which defines an intake. In an operative configuration, the hood (5) is positioned within an overhead volume corresponding to a space directly adjacent to an exhaust of a locomotive. In a standby configuration the hood (5) does not occupy the overhead volume.

Description

Ventilation devices, systems and methods for train depots

Field of the invention

The present invention relates to devices, systems and methods for ventilating train depots.

In particular, the present invention relates to the ventilation of vehicle enclosures via the localised extraction and removal of exhaust fumes emitted by vehicles that utilise a combustion engine, such as diesel locomotives.

Background to the invention

Combustion engines, such as those of diesel-power locomotives, generate significant exhaust fumes that can be deleterious to health, especially when these fumes are emitted within the relatively confined area of a train depot. This is particularly a problem when the engine of a locomotive must be kept running to move a train into position, or during the performance of certain maintenance tasks by maintenance staff - even if the train is stationary.

Whilst general-purpose ventilation systems are commonplace, these are often either too small to generate the air extraction rates needed to clear the air, or too large to be easily or efficiently retrofitted to existing train depots.

In particular, there can be limited space within a train depot for accommodating ventilation systems: floor space next to train rails must be left relatively clear for maintenance staff. Conversely, a roof structure of the depot may not necessarily be able to safely hold the weight of ventilation systems that are powerful enough to provide the requisite air extraction rates.

It is against this background that the present invention has been conceived.

Summary of the invention

According to a first aspect of the present invention there is provided a ventilation device suitable for ventilating a train depot. Preferably, the ventilation device comprises at least one of: a support, an arm and a hood. Preferably, the hood defines an intake of the ventilation device.

Preferably, the arm extends transverse to the support, and connects to it at a proximal end of the arm. Preferably, the hood is positioned along the arm, ideally between the proximal end and a distal end of the arm. Ideally, the support is a vertically-extending support allowing the transversely-extending arm to be supported away from and approximately parallel to the ground.

Preferably the device is moveable between an operative configuration and a standby configuration. In the operative configuration, the hood may be positioned within an overhead volume corresponding to a space directly above and/or adjacent to an exhaust of a locomotive. In the standby configuration, the device substantially does not occupy the overhead volume. Moreover, in the standby configuration, an electric train can safely travel through a depot in which the ventilation device is installed with a pantograph of the electric train being able to pass through the overhead volume without collision.

Preferably, the hood is variably positionable at various locations within the overhead volume when the device is in the operative configuration. Advantageously, this allows the hood to be dynamically positioned close to the exhaust of a locomotive, even if the exact position of the exhaust cannot be predetermined. Specifically, the locomotive can be variably positioned at one of many different locations along a rail, and so the ventilation device can be responsively adjusted to position the hood into close alignment with the exhaust of the locomotive, thereby maximising the effectiveness of ventilation.

Preferably, the arm is moveable relative to the support. Preferably, the arm is pivotally- connected to the support at the proximal end of the arm to enable pivoting movement of the arm relative to the support when moving between the operative and standby configurations.

Preferably, pivoting movement of the arm relative to the support is about a longitudinal vertical axis. This ideally coincides with the vertical axis of the vertically-extending support.

Preferably, the arm comprises ducting that is airflow-coupled to the hood. The ventilation device may further comprise a body that is mounted on the vertically-extending support. The body may comprise a fan unit for transferring air from the intake defined by the hood, via the ducting, to an exterior outlet.

Advantageously, locating the fan at the body reduces suspension weight on the arm, increasing reliability and allowing for a more lightweight and efficient construction of the arm.

Preferably, the arm connects via the body to the support. The device may comprise an electro-mechanical arm actuator preferably in the form of a motor-driven slide mechanism to which the hood is connected, the arm actuator being arranged to move the hood relative to the arm. Preferably, the arm actuator is arranged to slide the hood along the arm. The arm actuator may comprise or be connected to a belt drive mechanism. The arm may comprise adaptive ducting that maintains an airflow-coupled connection to the hood throughout movement of the hood along the arm. The adaptive ducting may comprise an expansible tube, such as a flexible hose and/or telescopic tubing.

Preferably, the support comprises a floor-mounted column. Advantageously, this reduces dependency on adequate support structures within the depot. Nonetheless, the support may instead comprise a connector for connecting to a depot structure. In other alternatives, the support may be mounted on to a moveable platform, such as a rail-mounted platform.

Preferably, the support is electrically non-conductive, at least in part. For example, the support may be predominantly constructed from glass-reinforced plastic (GRP). Preferably, the support comprises cladding that is electrically non-conductive.

Advantageously, this allows the ventilation device to be both highly effective in removing fumes generated by a train's combustion engine, but also does not interfere with electrically- powered trains. Specifically, in one configuration, the extraction hood can be positioned directly over the source of fumes emitted by a diesel-powered engine, but in another can be moved out of the way to prevent collision with a pantograph employed by electrically- powered trains that draw power from overhead power cables. Thus, the device can be used within a train depot that accommodates both diesel-powered and electrically-powered trains.

Preferably, the device comprises an operator interface configured to allow operator- controlled movement of the ventilation device. Preferably, the operator interface comprises a control unit accommodated at a user-accessible home position. Ideally, this is located on or within the support.

Preferably, the control unit is electrically-connected via an extensible cable permitting an operator to move the control unit, in use, away from its home position, and toward a position closer to the arm and/or hood. Advantageously, this allows the operator to stand away from the support, and closer to the hood to allow the operator to better judge the most effective positioning of the hood relative to the exhaust of a locomotive.

Preferably, the operator interface comprises at least one control element for controlling the movement of the ventilation device. Ideally, the at least one control element is biased towards a fail-safe position.

Preferably, the at least one control element comprises an arm-movement switch having: a first position that moves the arm relative to the support in a first direction, and a second position that moves the arm relative to the support in a second direction, opposite to the first direction. Preferably, the arm-movement switch has a third position, in between the first and second position, that ceases relative movement between the arm and the support.

Preferably, the switch is biased towards the third position. Advantageously, this improves the safety of the ventilation device.

Preferably, the operator interface comprises one or more control elements for controlling: relative movement between the arm and the support in a vertical direction; relative pivotal movement between the arm and the support about a vertical axis; relative movement between the hood and the arm in a vertical direction; sliding movement of the hood along the arm; and/or operation of a fan for fume extraction.

Preferably, the ventilation system comprises an automated positioning system. The automated positioning system comprises a camera positioned to view an operating area within which the hood is moveable. Preferably, an input from the camera is processed by the automated positioning system to safely position the hood close to the exhaust of a locomotive when the device is in the operative configuration.

According to a second aspect of the present invention, there is provided a system for ventilating a train depot. Preferably, the system comprising at least one ventilation device according to the first aspect of the present invention.

The system may comprise a depot, or component parts thereof. For example, the system may comprise a depot structure, such as a wall or roof structure, that separates the interior of the depot from an external environment. The system may comprise an exhaust duct leading through the depot structure to allow venting of fumes captured by the at least one ventilation device to the external environment. The system may comprises a depot structure to which a ventilation device according to the first aspect of the present invention is connected to, or positioned relative to.

The system may comprise a plurality of ventilation devices according to the first aspect of the present invention. The plurality of ventilation devices may positioned and arranged within the train depot to provide localised fume extraction across a series of overhead volumes that follow the path of a set of train rails.

According to a third aspect of the present invention, there is provided a method of ventilating a train depot. The method may comprise positioning a hood, that defines an intake of a ventilation device, within an overhead volume corresponding to a space directly adjacent to an exhaust of a locomotive during an operative configuration. The method may comprise positioning the hood outside of the overhead volume during a standby configuration. Accordingly, safe movement of train through or past the overhead volume is facilitated. It will be understood that features recited herein to be preferable are not necessarily essential to one or more aspects of the present invention. Additionally, features and advantages of different aspects of the present invention may be combined or substituted with one another where context allows.

For example, the features of the ventilation device described in relation to the first aspect of the present invention may be provided as part of the ventilation system described in relation to the second aspect of the present invention. For example, the system may comprise features such as the adapting ducting, the actuator, the operator interface, the automated positioning system and others as described herein.

Furthermore, such features may themselves constitute further aspects of the present invention. For example, the features of the adapting ducting, the actuator, the operator interface, the automated positioning system and other features themselves constitute further aspects of the present invention.

Brief description of the drawings

In order for the invention to be more readily understood, embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a front view of a ventilation device according to a first embodiment of the present invention;

Figure 2 is a sectional side view of the ventilation device, taken along the line E-E of Figure

1 ;

Figure 3 is a sectional side view of the ventilation device, taken along the line F-F of Figure 1 , and the reverse to that shown in Figure 2;

Figure 4 is a schematic overhead view of the ventilation device of Figure 1;

Figure 5 is a perspective schematic view of the ventilation device of Figure 1; and

Figure 6 is an overhead schematic view of a ventilation system that comprises a set of ventilation devices, corresponding to those as shown in Figure 1, installed within a train depot. Specific description of the preferred embodiments

Figure 1 is a front view of a ventilation device 1 according to a first embodiment of the present invention. The device 1 comprises a vertically-extending support 2, a body 3, an arm 4, a hood 5, and an exhaust duct 6. The body 3 is pivotally-mounted via a motorised remote- controlled slewing ring 7 to an enlarged upper portion 20 of the support 2. The support 2 has a vertical longitudinal axis X, and this coincides with the pivot axis about which the body 3 is able to pivot relative to the support 2. The slewing ring 7 comprises bearings to enable low- friction pivoting.

The support 2 is tubular and accommodates a control panel within its hollow interior. The control panel is accessible via an access door (not shown). The control panel comprises a mechanical power interlock and a common fire alarm interface. The common fire alarm interface is of a volt free contact type that will enable the device 1 and other systems to shut down upon receipt of a signal from a fire alarm system, separate to the device of the present embodiment, but commonly found within train depots.

The exhaust duct 6 emerges from an upper part of the body 3, and in practice is coupled with additional ducting that passes through the building structure of a depot within which the ventilation device 1 is installed for use. The exhaust duct 6 also approximately coincides with the pivot axis X, advantageously minimising movement such as flex of the exhaust duct during the operation of the device 1. This increases the reliability and longevity of the ventilation device 1.

The support 2 comprises a tubular column of rectangular cross-section, that is mounted to the floor of the depot. To this end, the support 2 terminates at a lower end with a flange 2a through which bolts can be tightened to fix the support 2 to a floor of a depot.

The outer cladding for support 2, and the material for shells of the body 3 and arm 4 are constructed predominantly from glass-reinforced plastic (GRP). Other materials apart from GRP may be used in alternatives, but these should ideally of a type that are strong, lightweight and not electrically-conductive. This is required to reduce the risk of electricity arcing from overhead cables, as may be provided within a depot servicing electrically- powered trains. The high strength-to-weight ratio of GRP also allows the system to be relatively narrow, typically sitting within the depth of existing depot structural columns therefore causing minimal obstruction to depot staff movement.

In alternatives, the support may be constructed from, for example, a steel sub-structure with an electrically-insulative outer cladding. This provides both the advantage of high strength to weight ratio as well as electrical insulation. Additionally, in alternatives to the presently-described embodiment, the column may have a different cross-sectional profile. Furthermore, in further alternatives, the support may not necessarily be floor-mounted. For example, the support may be in the form of a connector which links the device to a surrounding structure (e.g. column or wall) of the depot.

In further alternatives to the present embodiment, the support may be mounted on a moveable platform. For example, the moveable platform may allow transport of the ventilation device along rails to a location requiring ventilation. The rails may be separate from the train rails, but ideally run parallel to them. In such alternatives, the exhaust duct is adapted to allow transport of the fumes extracted by the device to an external environment.

However, in the embodiment shown in Figure 1, the floor-mounted support advantageously removes the risk of mounting the device to a depot structure which may not be strong enough. This arrangement occupies a minimal footprint within the depot, allowing servicing operatives to carry out their task safely.

Referring to Figures 2 and 3, which are sectional side views of the ventilation device 1 of the present embodiment, the arm 4 extends transverse to, and at approximately right-angles to the longitudinal axis X of support 2. The arm 4 is connected at its proximal end via the body 3 and slewing ring 7 to the support 2. The hood 5 is shown in Figures 2 and 3 as being positioned along the arm 4 towards the opposite, distal end of the arm 4.

The hood 5 has a frustoconical shape that funnels in air drawn through it to a first duct 40 of the arm 4, which in turn connects via a transformation piece 41 to a second flexible duct 42.

The first duct 40 is of rectangular cross-section, whereas the second flexible duct 42 is of circular cross section. Accordingly, the transformation piece 41 transitions smoothly between the two cross-sectional shapes, allowing air to pass via the transformation piece 41 with minimal interruption and turbulence.

The arm 4 is sized along its length to snugly accommodate each of the first and second duct 40, 42, with the outer region 45 of the arm 4 that accommodates the first duct 40 being of a smaller depth than the inner region 46 that accommodates the second duct 42. Whilst the top of the arm 4 presents a relatively planar, level surface, the underside of the arm is stepped, with the arm depth increasing step-wise from the outer region 45 to the inner region 46. Additionally, along the inner region 46, the arm depth increases gradually toward the proximal end of the arm - thereby addressing the increasing cantilevered load toward the proximal end. The arm depth arrangement described advantageously balances the strength of the arm against how slim and high the outer region of the arm 4 can be. The latter makes it easier for the hood to be positioned in the confines of the space between the top of a locomotive and the overhead line equipment within a depot. This, along with its non-conductive nature allows for the system to safely get close enough to the locomotive exhaust positions in depots which provide service for both diesel and electric locomotives.

The hood 5, the first duct 40 and transformation piece 41 are rigidly-connected to one another, and together define an air-flow channel to the second flexible duct 42. They are also mounted on a linear belt slide mechanism 43 that allows the hood 5 to slide along the length of the outer region of the arm 4. The belt slide mechanism 43 comprises an electro mechanical actuator 44 that can be activated to move the hood 5 to a chosen position along the arm 4.

The flexible duct 42 leads via an aperture in the body 3 to a fan inlet 81 of a centrifugal fan assembly 8. The fan assembly 8 comprises a motor 82 and a fan wheel 83 that are axially- oriented with the generally horizontal axis of the flexible duct 42 thereby maximising the efficiency with which air can be drawn in from the duct 42. The motor 82 turns impellers 83 that draw air from the fan inlet 81 and directs them upwards via a fan outlet 84 of the assembly 8 to the exhaust duct 6 via an intermediate offset duct 85. The intermediate offset duct 85 ensures that the exhaust duct 6 emerges from the body at a location that is axially- aligned with the vertical pivot axis X. As mentioned previously, this advantageously reduces the amount of relative movement between the exhaust duct 6 and a structure of the train depot to which the exhaust duct 6 is connected to vent fumes to the exterior of the train depot. The exhaust duct 6 lead to an exhaust cowl mounted on the external envelope of the depot (not shown). The fan in the present embodiment is a single inlet, singe width centrifugal fan, rated to handle relatively high temperatures (-200 degrees Celsius) and noxious fumes as typically emitted by combustion engine-based locomotives.

The upper portion 20 of the support 2 contains an electro-mechanical pivot actuator in the form of a slew motor 21 which is arranged to act between the support 2 and the body 3 to allow relative pivotal movement of the two. The pivotal movement of the arm 4 can, in principle, perform a full 360 degree rotation. However, the use of the ventilation device 1 of the present embodiment will be discussed in a context associated with a single rail road where a rotation of only 180 degrees is sufficient.

Figure 4 is a schematic overhead view of the ventilation device of Figure 1 , floor-mounted at a position next to a wall 90 of a depot 9, the wall 90 extending parallel to a pair of rails 91 via which trains can travel into and out of the depot 9. The ventilation device 1 is shown in an operative position in which the arm extends across the rails 91 at 90 degrees, and as such is positioned within an overhead volume 100 as depicted by the rectangular dotted shape in Figure 4.

The arm 4 can pivot so that it is oriented parallel to the rails 91 and wall 90, as exemplified by the dashed outline of the arm 4b and hood 5b extending to the left in Figure 4. Alternatively, the arm may extend to the right instead. In either case, this stows the arm 4, and the device 1 as a whole is positioned away from the rails 91. This puts the device into a standby configuration. This prevents interference or collision with a train passing along the rails 91 that may have a different height profile - for example, an electrically-powered locomotive having an extended pantograph unit mounted on its roof.

Referring to Figure 5, which is a perspective schematic view of the ventilation device 1 in the operative configuration, the overhead volume 100 corresponds to a space above a locomotive 101 - and so that which is generally adjacent to an exhaust 102 of the locomotive 101.

The exact position of the exhaust 102 of a locomotive can vary depending on the type of locomotive, and also the precise position along the rails 91 that the locomotive stops. Whilst positioning the hood 5 generally within the overhead volume 100 can serve to provide effective localised extraction of fumes emitted by the exhaust 102, the effectiveness can be further improved by moving the hood 5 to a position that is as close as possible to the exhaust 102.

To this end, the hood 5 is moveable along the arm, between an outer position at a distal end of the arm 4 and an inner position closer to the proximal end of the arm 4 as shown by the dashed shape 5a shown in Figure 4. This, in combination with the pivot movement of the arm 4 defines an arc-shaped operating area 53 across which the hood 5 is moveable. The arc-shaped operating area 53 is depicted schematically in Figure 4 as the region between the pair of dash-and-dotted arcs 51, 52 and this intersects with and entirely encompasses the overhead volume 100.

Referring back to Figure 5, the ventilation device comprises an operator interface in the form of a pendant control unit 11 which is electrically-connected via an extensible cable 12 to other electrical components of the device 1 such as the fan motor 82, the arm actuator 44 and slew motor 21. The pendant control unit 11 is cradled at a user-accessible "home position" in a holder 11a near the bottom of the support 2, allowing an operator easy access to the controls for operating the device 1. The extensible cable 12 conveniently allows an operator to pull the control unit 11 away from its home position, in use, and so improves the ease and reliability with which an operator can judge the position of the moveable hood 5, and so adjust it such that the hood 5 can be positioned as close as practical to the exhaust 102. For this first embodiment, the extensible cable 12 can be extended to a length of up to 4 metres long, and automatically retracts the control unit to the home position when released. To this end, the ventilation device 1 comprises a cable retraction mechanism incorporating a constant force spring, to allow safe retraction of the cable 12. In alternative embodiments, the cable may be longer or shorter, and may use a different extension/retraction mechanism (e.g. via a curly spring-back cable), and may be built into the support 2.

The control unit 11 comprises a series of control elements for controlling various operating functions of the device 1. For example, in the present embodiment, the control unit 11 has a motor selection interlock switch, with three positions, allowing for the fan 82, slew motor 21 or arm actuator 44 to be selected for movement or activation. A second common motor operation switch is functionally linked to the slew motor 21 and arm actuator 44, allowing respective slew and/or slide movement. Slew movement is relative pivotal movement between the arm 4 and the support 5 about the vertical pivot axis X. Slide movement is sliding movement of the hood relative to the arm and support.

The motor operation switch has three positions: with the slew motor 21 selected via the motor selection switch, a first position rotates the arm anti-clockwise about the axis X, a second position rotates the arm clockwise, and a third central position stops movement of the arm 4.

With the arm actuator 44 selected via the motor selection switch, a first position slides the hood position away from the support 2, a second position slides the hood position towards the support 2, and a third central position stops movement of the hood 5.

The motor operation switch is a "return-to-centre" switch that is biased towards the third central position, thereby establishing a fail-safe control element. Thus, accidental release of the switch due to incapacity of the operator safely ceases movement of the arm. Additionally, automatic stops prevent collision of the arm with structures such as the wall 90 regardless of operator input via the control unit.

This embodiment prevents simultaneous movement of the arm and the hood, but advantageously reduces complexity and cost: only one return-to-centre switch is needed.

In alternative embodiments, the control unit 11 may comprise individual motor operation switches for the slew and slide motor operations.

The control unit 11 also comprises fan-on and fan-off switches for respectively activating or deactivating the fan motor 82. Furthermore, the control unit 11 of the present embodiment comprises an Emergency Stop button for ceasing all fan and actuator activity, a key switch for enabling an otherwise disabled control unit 11 to authorised key-holding operators, and status indicia, such as LED lights to provide feedback to an operator about the status of the system. For example, LED indication which signifies when the extract fan is running, to indicate a fault or warning, or to indicate a boom arm and/or hood movement.

Further safety features are provided, including sounders and beacons. These activate during movement to provide audio and visual alerts to depot staff.

Figure 6 is an overhead schematic view of an example ventilation system 10 that comprises a set of ventilation devices 1a, 1b, 1c, corresponding to those as shown in Figure 1. These are installed within a train depot 9 of a single road type - i.e. having only a single pair of rails 91 passing through it. In this example, three ventilation devices are alternately positioned either side of the rail road, such that their respective arc-shaped operating areas 53a, 53b, 53c mosaic with one another to substantially encompass the entire length of the rail road.

This provides a high level of flexibility about where a locomotive can be stabled.

To simplify operation of a ventilation system 10, and the further promote safety, the system 10 comprises a common control panel 110. This is typically wall-mounted, and operatively connected to the devices 1a, 1b, 1c to allow their simultaneous control. In use, an authorised depot operator activates the common control panel 110. The common control panel has a switch for selecting electric or diesel train operation. This governs whether the set of ventilation devices 1a, 1b, 1c are placed into their standby configuration, arms parallel to the rail road (for electric trains) or can move into their operative configurations (for diesel trains) where the arms overhang the rails 91. In particular, selecting diesel operation, and pressing a start button will signal all devices 1a, 1b, 1c on that road, and cause them to move to a default operative configurations as shown in Figure 6 - specifically with each arm being perpendicular to, and overhanging the rails 91.

Once in their default operative configuration, the fan of each device 1a, 1b, 1c will turn on, typically within a range of 30%-75% of full power output. Turn-on delays (e.g. less than 10 seconds) can be used to prevent sudden in-rush of current. The fans will, by default, remain active for a predetermined period (e.g. 10-30 minutes), and then turn off. A locomotive can then be positioned along the road, and one of the nearest devices can be selected for manual adjustment, via its respective control unit, to ensure that its hood is located as close as possible to the exhaust of the locomotive. Once positioned, the fan power can be increased for that nearest ventilation device closer to full power output. In certain embodiments, for safety reasons it is not possible to simultaneously operate a fan of a device, and move the arm or hood. In these embodiments, movement of the arm and hood occur independently and alternately with activation of the fan.

To enable an electric train to be moved onto the road, the devices will be required to be moved out of the way so as not to impede the train pantograph. In this case, selecting electric train operation via the switch on the common control panel 110, and pressing the start button causes the devices to move such that their arms are parallel to the road. Where all devices were previously in an operative configuration, they typically move, one after the other, to their standby configuration.

In alternatives embodiments that have multiple roads, a common control panel would typically control a set of devices for each road in accordance with the above-described method.

In further embodiments, a ventilation device, positioned between a set of two rail roads can serve either one of those roads via a 360 degree pivoting action.

The approximate dimensions of various parts of the ventilation device 1 according to the first embodiment shown in Figure 1 are listed as follows:

Length of arm, from proximal to distal end - 6.5 metres

Height of hood from a level floor to which the support is mounted - 4 metres

Width of channel defined within the arm - 0.7 metres

Length from longitudinal axis X to distal end of arm - 7 metres

Length of travel of hood along arm - approx. 2.2 metres.

Diameter of flexible ducting - 300mm

Typical range of cross-sectional areas of ducting between hood and fan - 0.06 - 0.08m²

Cross-sectional dimensions of first ducting: 400mm wide ^c 150mm deep Footprint - i.e. foundations/base - 0.8m x 0.8m

Cross-sectional dimensions of the square profile support - 0.4m x 0.4m

- Area within which hood is positionable, across an arm pivot angle of a 180 degree - 60m² It will be understood that the above measurements for the ventilation device according to the first embodiment are approximate, and purely exemplary for this particular first embodiment of the invention. Dimensions for other embodiments will vary, and moreover would be chosen to achieve best fit for a specific depot.

In particular, it is envisaged that the length of the arm, from proximal end to distal end would vary depending on the space available within a depot, and the required sweep area of the hood. Arm lengths of, for example, 4.5m and 2.2m are likely to be useful where a shorter arm lengths are desirable. In these two alternatives, dimensions for the length of travel of the hood along the arm would be approximately 2m and 1m respectively.

Nonetheless, from the above, ratios can be determined that characterise the ventilation device. In particular, for embodiments that are floor-mounted, the operating area of the hood (over an arm pivot angle of 180 degrees) is at least 25 times larger than the footprint of the support, more preferably at least 100 times larger, and in the case of the first embodiment, over 200 times larger. This epitomises the ability of the ventilation device to flexibly handle highly-localised fume extraction, whilst being independent of depot structure limitation and also being unobstructive to depot staff.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.

For example, the ventilation device of further embodiments of the invention may comprise additional degrees of freedom. The hood may be moveably-mounted to the first duct such that it can raise and lower relative to the first duct, whilst also maintaining a reliable air-flow coupling with it. This allows the hood to be moved in the vertical direction closer to, or even completely enveloping an exhaust of the locomotive - thereby increasing the effectiveness of highly-localised fume extraction.

Alternatively, effective vertical displacement of the hood relative to the exhaust of a locomotive can be achieved in other ways, such as using an appropriate actuator to: move the arm relative to the body, the body relative to the support, and/or vertically-adjust the support. In such cases, the control unit comprises control elements for controlling, for example, the relative movement between the arm and the support in a vertical direction, and/or the relative movement between the hood and the arm in a vertical direction.

Further alternative will be apparent to those skilled in the art. Thus, it is intended to embrace all such alternatives, modifications and variations that fall within the scope of the appended claims.

Claims

1. A ventilation device for ventilating a train depot, the ventilation device comprising: a support; an arm extending transverse to the support, and connected to it at a proximal end of the arm; and a hood, positioned along the arm between the proximal end and a distal end of the arm, the hood defining an intake of the ventilation device; wherein the device is moveable between an operative configuration in which the hood is positioned within an overhead volume corresponding to a space adjacent to an exhaust of a locomotive, and a standby configuration in which the device does not occupy the overhead volume.

2. The ventilation device of claim 1 , wherein the hood is variably positionable at various locations within the overhead volume when the device is in the operative configuration.

3. The ventilation device of claim 1 or claim 2, wherein the arm is pivotally-connected to the support at the proximal end of the arm to enable pivoting movement of the arm relative to the support when moving between the operative and standby configurations.

4. The ventilation device of any preceding claim, wherein: the arm comprises ducting that is airflow-coupled to the hood; and the ventilation device further comprises a body mounted on the support, the body comprising a fan unit for transferring air from the intake defined by the hood, via the ducting, to an exterior outlet.

5. The ventilation device of claim 4, wherein the arm connects via the body to the support.

6. The ventilation device of any preceding claim, wherein the arm comprises actuator to which the hood is connected, the actuator being arranged to move the hood relative to the arm.

7. The ventilation device of claim 6, wherein the arm comprises adaptive ducting that maintains an airflow-coupled connection to the hood throughout movement of the hood along the arm.

8. The ventilation device of claim 7, wherein the adaptive ducting comprises an expansible tube, such as a flexible hose and/or telescopic tubing.

9. The ventilation device of any preceding claim, wherein the support comprises a floor- mounted column.

10. The ventilation device of any preceding claim, wherein the support comprises an electrically non-conductive material.

11. The ventilation device of any preceding claim, further comprising an operator interface configured to allow operator-controlled movement of the ventilation device.

12. The ventilation device of claim 11, wherein the operator interface comprises a control unit accommodated at a user-accessible home position on or within the support.

13. The ventilation device of claim 12, wherein the control unit is electrically-connected via an extensible cable permitting an operator to move the control unit, in use, away from its home position, and toward a position closer to the arm and/or hood.

14. The ventilation device of any one of claims 11 to 13, wherein the operator interface comprises at least one control element for controlling the movement of the ventilation device that is biased towards a fail-safe position.

15. The ventilation device of claim 14, wherein the at least one control element comprises an arm-movement switch having: a first position that moves the arm relative to the support in a first direction; a second position that moves the arm relative to the support in a second direction, opposite to the first direction; and a third position, in between the first and second position, that ceases relative movement between the arm and the support; wherein the switch is biased towards the third position.

16. The ventilation device of any one of claims 11 to 15, wherein the operator interface comprises one or more control elements for controlling: relative movement between the arm and the support in a vertical direction; relative pivotal movement between the arm and the support about a vertical axis; relative movement between the hood and the arm in a vertical direction; sliding movement of the hood along the arm; and/or operation of a fan for fume extraction.

17. The ventilation device of any preceding claim, further comprising an automated positioning system having a camera positioned to view an operating area within which the hood is moveable, an input from the camera being processed by the automated positioning system to safely position the hood close to the exhaust of a locomotive when the device is in the operative configuration.

18. A system for ventilating a train depot, the system comprising at least one ventilation device according to any preceding claim.

19. The system of claim 18, further comprising a depot structure, such as a roof structure, that separates the interior of the depot from an external environment, the system comprising an exhaust duct leading through the depot structure to allow venting of fumes captured by the at least one ventilation device to the external environment.

20. The system of claim 18 or claim 19, comprising a plurality of ventilation devices according to any one of claims 1 to 17.

21. The system of claim 20, wherein the plurality of ventilation devices are positioned and arranged within the train depot to provide localised fume extraction across a series of overhead volumes that follow the path of a set of train rails.

22. The system of claim 21, wherein each hood of the plurality of ventilation devices is moveable within a unique operating area, the operating areas substantially mosaicking together.

23. A method of ventilating a train depot, comprising: positioning a hood, that defines an intake of a ventilation device, within an overhead volume corresponding to a space adjacent to an exhaust of a locomotive during an operative configuration; and positioning the hood outside of the overhead volume during a standby configuration, thereby allowing safe movement of train through or past the overhead volume.