FIGURE 14.-Weapons effects radii for various yields.

outside the proving ground because only there are the yield and the burst points reasonably certain.

One can, however, adopt a minimum design pressure criteria. That is, a shelter which will not fail below a stated overpressure. Now, the following slide, figure 14, will aid in examining this point a little further.

10,000

100,000

This figure concerns the 30-man underground shelter we just described and shows the yield of devices on the bottom, versus the ground distance from the burst on the side. It shows the protection which would be provided from blast, and neutron radiation. Prompt gamma radiation could be included, but its curve would lie far below the other curve.

The overpressure line is the straight line and it represents 100 pounds per square inch. Again no allowance has been made for the effect of longer duration of blast waves from larger yields.

The line represents the value for which this particular shelter was designed. That is 100 pounds per square inch, a minimum pressure standard. The fact that the shelter showed no signs of failure in this vicinity indicates that its marginal pressure would be represented by a line laying somewhere below the line shown.

Now, the line below indicates survival of the structure either closer to the same yield, or at the same distance from a considerably larger yield.

Now, the point I would like to make is that even though this shelter might be considered overdesigned, which implies that maximum economy has not been achieved, the overdesign begins to lose its significance in the uncertainty as to the employment of enemy weapons, because one is never certain whether the enemy is going to drop a weapon of known yield at precisely a given distance; whether it will be the same yield at a closer distance or a larger yield at a greater distance.

The practical question becomes, then, what design can provide the most protection for a given number of dollars?

For each shelter design, a graph similar to the one shown could be prepared, together with its costs. The best shelter design for a specific location could be chosen from a group of such charts by reconciling the cost with the funds available and the degree of protection provided with the protection desired, the last being based on consideration of the proximity of the probable targets.

Before continuing, I would like to summarize certain points I have already made, as well as a few new ones.

Aboveground structures make the least desirable personnel shelters. Structures entirely below ground offer the most protection.

Full-scale structural testing of shelters should be limited to those which involve a new design concept, or procedure, and there are a number of those. For example, the corrugated metal pipe structures. That area is not well known at all.

Precise value for structural failure is not required because the significance of overdesign is lost in the uncertainties of enemy weapon employment. This point perhaps is most important, that the technical problems of neither blast loading nor structural response are obstacles to adequate shelter design at the present time and I am excluding radiation. This does not mean that we should not do continued testing.

Continued tests will give us more refined information. Information which we would like to have. But progress on shelters certainly is not being held up by a lack of information available at the present time.

It was my understanding you gentlemen are particularly interested in shelter costs. It is unrealistic to talk about costs except with reference to a particular shelter type. We may think of shelters according to the primary protection they provide as blast, or fallout shelters or according to their adaptability to family or larger groups. Το place undue emphasis on any one of these attributes is like selecting one style of dress for all purposes, all climates, and all people.

Mass or group shelters are required for industrial or commercial establishments as well as for public places. Family shelters are required for smaller groups. Either should be quite close or preferably attached to or made a part of the main structure.

Blast shelters should be provided at and around likely targets, fallout shelters for rural and outlying communities. Combinations of types will obviously be required. No one type fits all needs.

In dealing with costs, the question of family versus group shelters can be sidestepped by considering cost per occupant, if one keeps in mind that the cost per person may logically be 2 or 3 times as much for a shelter accommodating only 2 people say, a family shelter accommodating a couple as a shelter accommodating 30 people. The cost of 1 accommodating 300 people will decrease only slightly below that of a 30-man shelter. This, however, is not valid argument against small family shelters for the smaller shelters have the advantages of greater dispersion and availability to the family.

Let us look at an example of actual shelter costs. The fact that these costs have been derived from shelters built at Nevada does not mean they should be discredited. They should only be corrected.

The 30-man group shelter discussed earlier was built to withstand 100 pounds per square inch and cost about $1,100 per person_when built at the Nevada test site. Construction costs at the Nevada test site were at that time roughly two and a half times the cost of equivalent construction in an average city.

Thus a group shelter would cost about $440 per person if built outside NTS-the Nevada Test Site.

Two further savings could be made. The shelter could be lengthened to accommodate more people without any significant increase in the cost of entrances and the space provided for ventilating equipment and so forth.

Also, costs would be or could be reduced by the construction of large numbers of identical shelters. At a generous estimate, the cost could probably be reduced to $300 per person, excluding land and equipment.

Mr. HOLIFIELD. Now you are referring to a specific type of shelter? Mr. VORTMAN. I am referring in this case to the reinforced concrete 30-man shelter we saw in the drawing shown earlier.

Mr. HOLIFIELD. And that had walls and ceilings of what thickness! Mr. VORTMAN. The ceilings were 1 foot 9 inches and the walls 1 foot 3 inches thick.

Mr. HOLIFIELD. Was that level with the ground or covered with dirt?

Mr. VORTMAN. It was covered with dirt, between 5 and 6 feet of dirt over the top of the shelter and the cover dirt was level with the ground. There was nothing aboveground. That was the shelter that had the sliding reinforced-concrete door at ground level.

Mr. LIPSCOMB. Was that just a blast shelter, or would that be for blast and radiation both?

Mr. VORTMAN. Blast, neutron radiation, and gamma radiation was measured on that particular test. It did provide adequate protection from blast and from gamma radiation. The protection from neutron radiation was a point in doubt which I mentioned earlier. Mr. LIPSCOMB. You say that was a 30-man shelter?

Mr. VORTMAN. Yes.

Mr. LIPSCOMB. How long do you believe people should be able to live inside such a shelter?

Mr. VORTMAN. I would like to mention that point a little later if I may.

Mr. LIPSCOMB. You mentioned $300 per person, estimated, excluding land and equipment?

Mr. VORTMAN. Excluding land and equipment.

Mr. LIPSCOMB. Have you given any estimate to the cost of the equipment for a 30-man shelter?

Mr. VORTMAN. No; that I have not. I am going on the basis of costs which were provided at the Nevada test site which did not include equipment. Obviously, there was no cost included for land. Mr. LIPSCOMB. That was just a shell?

Mr. VORTMAN. Yes.

Mr. HOLIFIELD. Now, of what type equipment do you speak?

Mr. VORTMAN. I am speaking here, for example, of ventilating equipment. Perhaps one might want a small generator if one desired to have electric power for light or heat. Anything of that sort. Mr. HOLIFIELD. You might even go back to candles as an emergency for a few days.

Mr. VORTMAN. That is certainly a possibility.

Mr. LIPSCOMB. But you would use up air, which is vitally needed in a shelter.

Mr. HoLIFIELD. Incidentally, before we leave that point of air, it is possible to construct hand-operated ventilating devices which will pull the air through materials which will filter out the radioactive particles, is it not?

Mr. VORTMAN. Yes; there are a number of practical solutions and I am sure those which you describe were tested during Operation Plumbbob, and will be described by someone else later.

Also, Dr. White used a rather interesting system during his animal experiments: A compressed air bottle which gradually bled air into

the room.

The buried multiplate pipes which I mentioned earlier, project 34.3, the costs were about $9,500 for each 1 of the pipes, or on the basis of 10 persons, about $950 per person shelter.

The $9,500 did not include a satisfactory blast-proof entrance, because these had no such entrance but were completely buried and had to be dug out later. There was a small entrance shaft part way to the

surface.

Construction of such a blast-proof entrance would probably about double the cost of such shelters. Such a shelter then would cost about $1,900 per person at Nevada, or about $760 per person elsewhere. A lengthened shelter, mass produced, perhaps prefabricated, would probably cost about $525 per person for about 250 pounds per square inch protection.

Again, it must be kept in mind this type shelter is not suitable for use where water tables are above 24 feet.

Now, let's examine an overall cost for the Nation of a shelter program, using these assumptions: First, about 60 million rural Americans would require fallout protection. Blast protection of varying degrees must be provided for the rest of the population. Of the remaining 110 million, approximately 45 million, or about 40 percent. are in the urban working force, and would require shelter space both at home and at work.

This gives a total of around 155 million persons for whom shelter would be built. This may seem overly generous at first, but note that I have made no allowance for shelters in places of public activity such as schools, churches, and so forth.

Now, based on the shelter costs mentioned earlier we can assume the costs as follows:

These were derived merely from the 2 points of cost I have given you earlier based on 2 shelters and if 1 makes a plot of the cost versus pressure level of protection, drawing a line through these 2 points and rounding this off to a nice even $100 unit, the cost would be as shown above.

Now, let's look at the cost of a nationwide program based on these units costs and the assumptions that I mentioned earlier.

A fallout program only, the total cost would run around $22 billion. Fallout only for the rural people plus 25 pounds per square inch protection in the urban areas, $37 billion.

Fallout only rural but 100 pounds per square inch protection in the urban areas, $53 billion, and for the latter case, fallout only, 500 pounds per square inch, urban, $115 billion.

Now, someone may want to point out that persons living in small towns are not likely to be in target areas which would require blast protection.

That is persons living in small towns would probably require only fallout protection.