The exhaust air pipes except, initially, those above the toilets and the emergency pipes were contained inside the air induction pipe until about a meter from the air induction vent where they turned at right angles and were vented to the air. The thicknesses of the metal of these air exhaust pipes, within the induction pipe, were thin and made of aluminium allowing a good heat transfer to the forced inducted air. The inducted air was sucked into the shelter by fans and the exhausting, of this air, was by internal pressure. The external air was sucked in through a specially designed very efficient fan, within this induction tube, the exhaust tubes passing outside of the fan restriction through sealed holes. All air vents, except those of the downward sloping emergency pipes and the exhaust air pipe over the toilet used during the initial air instability (when they were blocked) and high rainfall period, were designed as heat exchangers with piping as previously described.
This arrangement was applied for two reasons. Primarily to maintain as much heat energy as possible within the shelter and secondly to reduce the heat signature visible to unwanted guests. In the unlikely event that it became too hot within the shelter, due to impact material heating the atmosphere and possible fires, we would then use filtered emergency ventilation pipes and the now unused generator exhaust pipes on the upper floor.
A continuing potential problem, during the design phase, was how long the aluminium pipes would last in the case of highly acidic precipitation. Fortunately, while we were sheltered, this was never a problem. The induction and exhaust vents could be found on all floors. They could, during the deluge and pressure fluctuation periods, be closed from inside the shelter. It was found, however, that the opening of these pipes, after the event, was more difficult than expected. This required, a few weeks after the impact, some volunteers to go outside to open any vents suffering from this affliction.
All external pipes were protected from the ingress of water. Some were protected by bending over the pipe with a football in a cage to block the pipe in the event that water pressed it into the vent; something like a giant child’s snorkel. Most, however, were merely blocked by a physical obstruction.
All the external pipes had to be protected from direct contact with high velocity water. The pipes could be severely at risk in such situations. For this reason a security valve was installed in those pipes within structurally supported buildings. They were fitted with spring controlled shutters that could be pulled shut if a flow of water became noticeable inside the shelter. Lastly, as the risk to our shelter could have been extreme, all pipes could be closed by valves from within the shelter. Due to the potential water pressure that would occur on water leakage filling these pipes from top to bottom these additional water cut off valves were sited, for each pipe, on the habitation floor and their ultimate control maintained from that area.
The shelters main air tube had holes of various sizes (the smaller on the upper floor enlarged on each floor in sequence) into each floor of the shelter and there were several fans, both electrical and manual, to force the air onto the floors using the minimum of non manual energy. To ensure the air was reasonably distributed throughout the shelter air test gages were available to test the quality of the air at any point so that any necessary adjustments to air flow could be made.
There was insufficient time to fully test the populated shelter’s` ventilation system before the impact so it was necessary to perform such tests under operational conditions. This was potentially risky but, fortunately, worked well in practice. It resulted in acceptable air quality, with only minor adjustments, at all points; even when we later had a considerable influx of residents.
To reduce the flow rate of water over the shelter, from the hill south of the shelter which rises to about one hundred and fifty meters above the level of our shelter, beheaded trees (beheaded during the last days before the impact to reduce the effects of any blast or water on their root systems.) were supported with thirty, six meter long concrete poles inserted 4 meters into the ground to further break up the water.
To the west of the shelter was a sunken road which would considerably deflect the overall flow of water over our shelter. On the eastern side a small erosion river bed was increased in size to provide a better, from our point of view, path for the water to run off the hill. The earth removed from the river bed was added to the insulation over our shelter.
For the initial period of the disaster, and whilst it was available, the power for our shelter was obtained from the house supply. This was provided via two separate cable routes in two blocked (to prevent excessive pressure extremes and water from entering the shelter during the initial period after the impact) cable ducts into the shelter. We had decided on two separate cables in case one was cut prior to loss of this important power source. These cables (we installed eight in each cable duct) would later be used for the external sustainable generators of electricity (solar and wind) that we planned to set up when we considered we would be able to do so without risk to ourselves or our equipment.
The air in the shelters extension area was maintained in the same manner as in the shelter with considerable air being directed to the upper extension floor where there were four major partitioned areas. One was our main power station; two were the battery areas and lastly the main cooking area. The power station contained two of our main diesel generators (the remainder were stored on the food floor except one which was temporarily set up with connection to the exhaust and inducted air pipes set up for the deluge) with baffled exhaust vented to the outside air similarly disguised and protected in a rubbish area.
On this floor, in two well separated partitioned rooms on opposite sides of the central passageway sealed from the main edifice by almost air tight doors with a valve directing overpressure air into the rooms, were the two lead acid batteries. Each battery room had two vents (both blocked during the period of the impact, when the charging of the batteries also ceased, and the whole was protected from the ingress of water) to the outside air to remove any generated hydrogen. Having both these batteries, though separated, on the upper floor was a calculated risk but the necessity of removing dangerous hydrogen gas had settled the matter.
In addition we also had the fifty volt capacitor battery on the food floor which was available as our final reserve of energy if required. This was stored on the food floor extension area this being well away from the general population. It was capable of providing considerable stored electrical energy if the lead acid batteries should be damaged or destroyed.
The lead acid battery cells’, being our main secondary energy support, were supported on rubber footed pallets. These pallets were there to provide some protection from possible impact effects. We were worried about the consequences if some of the glass cells of the main lead acid batteries were damaged. Though we had spare cells and plates and a good quantity of acid in well protected containers, in an external store, the production of dangerous gases from the leaking acid, even within our sealed one way valved doors, was a potential disaster. This reinforced our decision to isolation them from the main shelter. We had also placed strong alkaline chemicals in the battery rooms to moderate any possible effects and had a pair of appropriate gas masks and protective clothes hanging externally on each door
The animal and recreation/agriculture areas on each floor were separated from eachother, by concrete partitions set about 1.5 meters in height, into three separate areas with access to each via a gate. The areas allocated to the animals consisted of half the floor split in to two equal areas. One area, the most distant from human accessibility, was allocated as a cow paddock; which included a bull. Next allocation was for the goats. One third of each of these animal areas was partitioned for baled straw. The partition was movable as the straw was used to allow the animals a greater area.
To increase the scavenging area for the chickens they were able to pass between the two animal areas through a small hole in the gate. Each floor had a chicken hutch in the goat area. The chickens would occ
asionally be driven into the garden areas to allow them further scavenging areas.
The other half of the animal floors were allocated to human relaxation and vegetable gardening; the latter taking a modest portion of each floor area. The upper goat area and garden was used specifically as human rest areas and a relatively high level of generator lighting was provided here for up to 14 hours a day.
Outside of the generator supported lighting period residual, though minimal, lighting was provided via LED units supported by the battery. A small area on the upper animal floor was lit, by the battery, to a level sufficient for comfortable reading. This was to support those assigned to night duty who were primarily assigned to protect those valuable items, the animals, from any possible danger. There other duties were to monitor air quality, work the manual air pumps when necessary and to operate the hydroponic systems and fish tank filters.
During the night periods several battery powered fans were operating with others available to support the ventilation of the shelter if it should be necessary. The additional fans, however, were used very sparingly; and only when absolutely necessary. The full battery fan capacity was used only twice to my recollection. Both these occasions were due to a faulty battery within an alarm unit indicating a bad air situation and risks could not be taken.
The sump had four large swimming pools (future fish pools) and several smaller units. The swimming pool bodies were installed in the sump before the installation of the sump roof as they were too large to be installed afterwards. The fish themselves were, during the impact, stored in relatively small thick skinned plastic containers which would later be used to bring on fish eggs to hatch-lings. The tank vegetation and animals (mostly snails but included other animal types) were stored in the swimming pools which were initially filled with water and mud (largely obtained from the nearby lake) to a depth of about fifteen centimetres. After the earth shocks had reduced acceptably and before the water contamination levels became detectable these units were filled with water from the well to initially act as a water reserve.
When the salination level had reduced acceptably the fish allocated swimming pools would revert to their primary function; fish production. Some of our fish stocks were introduced into two of the pools. This water would, however, be available, as a last resort, for animal (including human) support until the well water had returned to acceptability. The functioning fish pools were filtered and aerated manually on a multi daily basis by our personal. All those allocated to the task, except the night guards, were volunteers and it became part of their daily task allocation.
The sump area had several small areas, normally isolated from the rest of the shelter, provided with moderate lighting during the day. Here were the fish, hydroponic units, two further herbalist garden areas and two beehives we would support as well as we were able. We stored a considerable quantity of our honey, separate from that for human usage, for the bee support. Some of these bees would be allowed into the garden areas to fertilize our crops where this could not reasonably be achieved by fans (air pollination), or by manual means.
The diesel fuel storage in the sump area consisted of sixteen top quality 500 litre double skinned plastic tanks on ground supported concrete and supported, in compression, by metal straps. These tanks, for additional protection, were placed on the thick rubber mats that had been obtained for this purpose. It was hoped, which proved to be the case, that these supports would sufficiently protect these valuable assets from the early effects of earth movements. Similar diesel storage was available in the extension areas where was they were also supported by the ground; to prevent the possibility of floor collapse.
All household gas bottles, except four, were stored, during the period of maximum danger, either in the outhouses or in a petrol store. These gas bottles were similarly protected on rubber matting but for further protection were taped together in groups of eight to ten bottles.
The four bottles in the shelter were similarly heavily protected. They were in the shelter to ensure that there was, at least, a single hot meal, for every inmate, every day for the first four to six days if the mains electricity failed. In this event the problem of ventilation had to be carefully monitored.
The cooking area was necessarily on the top floor of the extension area, in spite of the increased risk to our cooks. This area would be provided with special forced air ventilation during food preparation; after the air burst had past due to the burning of gas for the cooking of food within a limited space. The risk was taken as people tend to react well to a simple hot meal and trusted companions during periods of high stress.
The upper animal extension area had two, six meter square, water tanks which were actually large, one meter deep, flat bottomed, fibreglass swimming pools. These water tanks had distribution pipes to the lower area water storage. They were initially maintained nearly empty, to avoid damage, until after the primary impact effects had dissipated when they were immediately filled from the well water, as above; before the salination levels were assumed unacceptable for consumption (it was detectable).
Some water tanks, when their water storage task was no longer required, would be filled with soil that had been stored, in man portable sacks, in the extension area. Our small store of bagged peat was also stored here. This material had been stored in order to provide facilities for some very limited fresh food production and to provide some education in agriculture to our population.
The rest of this extension area was used for storage of items that we thought might be useful; this included old clothes, metal items (including copper wire) pipes (both metal and plastic though largely the latter), nails, scissors, electrical switches, several typewriters with associated stores and, as we had them, four medium sized amateur astronomical telescopes; these being of great interest to myself for future observations. Here we also stored some wood and coal burning stoves with accessories including suitable pipes, radiators, chimneys and seven metal baths; some of these were used, much later, to set up baths for the inmates in the upper extension area. We also planned to use the stoves to provide hot water for a central heating system should it prove necessary. Fortunately these stoves were never required for this purpose though we set up an emergency system to support the hospital.
Of special interest to our future convenience were four electric and three, good quality, old, manual sewing machines. These came with a great deal of associated equipment such as needles and thread. They were obtained either by purchase or some other means before knowledge of the disaster became universal. With these manual systems volunteers were able to repair clothes and other material needed by various projects even into the current period.
Later when we were able to produce cloth using previously purchased and internally manufactured looms with two spinning wheels; one antique and one a modern reproduction, cautiously upgraded to functionality. We were able to produce new clothes, though initially of rather poor quality, after a considerable learning period. Fortunately some of the required information for this work was obtained from our books and the rest by common sense and a study of the items resulting, some time later, in very acceptable quality clothes being produced.
We stored several camping stoves and lights; all of which were capable of being used with some or other of our different gas bottles. We also stored as much good quality cycling equipment (especially good mountain bikes) as we could obtain from whatever source. These were considered important for up to medium distance transport as we, unfortunately, had insufficient space, in the shelter, for horses. We hoped that some horses would survive in other human groups (for which we might bargain or possibly join with) or in the wild; we considered this latter possibility very unlikely. We did not expect any large animals, including humans, to survive for any period in the open.
The only animals, other than humans and animals protected by them, we expected might survive in reasonable numbers were those living in burrows, such as rabbits. These animals we hoped, at some later time,
to trap and add to our food variety. Any traps we produced would be as non lethal as possible as we hoped to farm these animals for both their fur and meat; both being useful supports to our clothing and survival. We did not originally support rabbits as we believed, or rather hoped, they would survive. If they did not it would have been of little consequence as their sustenance would not have survived and we had little of that available.
The lower animal extension area was similarly used for items that we considered might be of use at some later time. Some of our weapons and ammunition were stored there and a narrow area was set aside for military training; including air rifle shooting. This area included several stationary bicycles and treadmills adapted with fifty volt alternators connected to car batteries. The alternators and non deep cycle batteries we stored here had been removed from our and any other abandoned vehicles we could find. From these we also took any items we considered might be of value to us. The batteries, charged in this manner, were used with entertainment systems to reduce slightly the load on the generators. The amount of gas produced by charging these batteries was considered acceptable but we monitored the area regularly to observe the effects of our efforts.
We had obtained three medium sized manual wine presses which we stored in the hope that they would prove useful later; possibly as part of a printer system. This latter idea arose when sorting through donated material we found about thirty five kilos of old printing type made of a lead-based alloy intended originally as part of our lead store. There was no type plate and the quantity of type was insufficient but it would give us a start some time later when we redeveloped paper production.
Our asteroid survival: A fictitional history of the ten year survival of a large ELE asteroid impact by a small, pre advised, group Page 9