B1 B2 = 45cm – C1 C2 = (the narrow vertical slot continues above C1) – D1 D2 = Standard UK scaffolding bar (5cm) – E1 E2 = 20cm square bracket with 4 corner – F1 F2 = 20cm (although exact size is easily changeable at the point of installation) – Features of the Design Essentially the gate consists of a single horizontal scaffolding bar and therefore has no impact on airflow. The scaffolded bar embedded in the floor prevents digging underneath the main removable bar. The gate provides two large bat opening, above and below the main removable bar. The exact vertical positioning of the removable horizontal bar is adjustable, as part of the licence agreement process. The gap between the two scaffolding bars opening) will be 20cm high and > 40cm wide [See note below about aperture size]. The central bar can be removed by opening the padlock with a key. Alcoves on either side passage walls will need to be filled / flattened with concrete to provide a flat surface to bolt the supporting brackets to. The brackets are required to firmly hold the scaffolding bar in exactly the right vertical position, thereby maintaining the dimensions of the bat opening. The location of the gate is in one of the wider sections of the crawl, ie. the bat’s flight is much more constricted elsewhere in the entrance series. Risks The gap between the two horizontal scaffolding bars is dangerously close to the size through which a determined caver could squeeze. We understand that the required bat aperture is 40cm wide by 20cm high. A caver getting stuck between rib cage and pelvis, could be in a perilous position and require rescueing. Reduce the height of the aperture by as little as 2cm, would make the gate much safer. Would this be possible? Note that there is a similar sized second aperture above the main bar. There is a history of vandalism affecting entrances to Ogof Draenen. It is likely that this gate will similarly be vandalised at some point.
B1 – B2 = 45cm C1 – C2 = (the narrow vertical slot continues above C1) D1 – D2 = Standard UK scaffolding bar (5cm) E1 – E2 = 20cm square bracket with 4 corner F1 – F2 = 20cm (although exact size is easily changeable at the point of installation) Features of the Design Essentially the gate consists of a single horizontal scaffolding bar and therefore has no impact on airflow. The scaffolded bar embedded in the floor prevents digging underneath the main removable bar. The gate provides two large bat opening, above and below the main removable bar. The exact vertical positioning of the removable horizontal bar is adjustable, as part of the licence agreement process. The gap between the two scaffolding bars opening) will be 20cm high and > 40cm wide [See note below about aperture size]. The central bar can be removed by opening the padlock with a key. Alcoves on either side passage walls will need to be filled / flattened with concrete to provide a flat surface to bolt the supporting brackets to. The brackets are required to firmly hold the scaffolding bar in exactly the right vertical position, thereby maintaining the dimensions of the bat opening. The location of the gate is in one of the wider sections of the crawl, ie. the bat’s flight is much more constricted elsewhere in the entrance series. Risks The gap between the two horizontal scaffolding bars is dangerously close to the size through which a determined caver could squeeze. We understand that the required bat aperture is 40cm wide by 20cm high. A caver getting stuck between rib cage and pelvis, could be in a perilous position and require rescueing. Reduce the height of the aperture by as little as 2cm, would make the gate much safer. Would this be possible? Note that there is a similar sized second aperture above the main bar. There is a history of vandalism affecting entrances to Ogof Draenen. It is likely that this gate will similarly be vandalised at some point.
Drws%20Cefn%20Gate%20-%20Draft%200-1.docx