There was no question but what the conventional powerplants could be obtained. However, before evaluating a nuclear powerplant it was necessary to prepare a feasibility design of such a plant."

All operating characteristics and costs have been developed on this feasibility plant. You see that it is made up of a single reactor vessel in the background at the center of the circle.

This low enriched uranium oxide reactor would heat pressurized water but would not boil it because it would be under pressure.

This primarily coolant would then be circulated by means of pumps through steam generators where the secondary steam would be generated.

This would be saturated steam and would be used to drive rather conventional steam turbogenerator sets. You see around this entire core and pump and steam generator assembly a circle which in fact represents a sphere. This is the containment vessel and it is designed to contain any radioactive material, gaseous or otherwise, which might develop due to what is known as a maximum credible accident. That means that things really go bad. This is designed for a pressure of somewhere in the neighborhood of 500 pounds per square inch. This ball is in the neighborhood of 45 to 50 feet in diameter.

Surrounding the containment vessel is the shielding which is necessary to protect surrounding spaces from radiation. Note that there is a necessity for great structural support under this. This portion that you see here by the way is in the neighborhood of 1,600 tons.

This is a plan view of the reactor and while it is a little bit con fusing perhaps you may be able to see that there are three loops. This means that the primary coolant will be withdrawn from the reactor and circulated through three separate steam generators.

Any two of those steam generators are capable of providing full power for the vessel so that we do have in fact a 50-percent reserve capacity in case there is any kind of a difficulty with one of the loops. The next slide.

This is another view which shows how this reactor assembly fits into the hull. This is a cross section through the middle of the ship. Notice the comment in the area to the right which indicates that it is necessary in order to protect the reactor against damage due to collision.

This is a heavily reinforced area.

The next slide, please.

Perhaps the only figure of real interest in this chart is the figure in the first column to the left, the first yellow column, the fifth number up from the bottom which shows a fuel weight of somewhere over 2,000 tons. This fuel was added in the original study in order to bring the total weight of the machinery plant and fuel up to the same level in all four of the vessels in order to allow a comparison.

Actually, this figure of 2,000 tons does represent the capacity to carry liquid cargo both to other conventionally powered vessels and also to bases. While there is only one reactor in the vessel that we contemplate, it does have an auxiliary boiler which would be able to develop enough power to get the vessel back home in the remote possibility that there was some kind of casualty to the reactor that could not be repaired.

However, we do feel that that is a remote possibility.
The next slide, please.

These figures show the relative capital costs of one propulsion plant only.

This does not represent the entire ship and these figures are in 1966 dollars. Notice that over the entire power range the nuclear powerplant is more expensive to buy on a ship-per-ship basis. The next slide, please.

This is the same information reduced to a 30-year life cycle. These are capital costs for the propulsion plant only spread over 30 years. The next slide, please.

Here the picture in inverted with the nuclear fuel costs being significantly lower than conventional fuel costs, the diesel being next most competitive, then the oil-fired steam, and finally the gas turbine the most expensive to operate from the point of view of fuel. The next slide, please.

This is the composite picture for the propulsion plant only and I should say that these figures include initial procurement, initial training, payment of the crew, engineering design services, maintenance and fuel-in other words everything to build and make the propulsion plant run for 30 years.

This shows that from this point of view the nuclear plant is competitive on a ship-per-ship basis with the best of the conventional vessels-the diesel.

I should add one other comment to that. Notice that this shows the variation of the total annual economic costs as a function of the number of plants which are bought at the same time.

Obviously, there are benefits to be derived from buying more than one plant at a time.

It does show that in the neighborhood of five plants there is a

crossover.

The next slide, please.

Now, what is the effectiveness of these ships? Originally, the mission was defined for the purpose of this study as being able to cruise 10,000 miles, operate 120 days in the ice, and return.

This is the mission profile. The first area to the left shows the actual icebreaking time, about 33 percent of the year, 120 days, with part of that operation at reduced power due to the fact that the ice just isn't heavy all the time.

The next block to the right shows the basic transit time to and from the icefield.

It says that if you have a fully effective icebreaker it will take you about 160 days away from your home port in order to break ice for 120 days.

However, conventionally powered ships cannot perform this mission without refueling and it is necessary for them to come out of the icefield and either be refueled by some kind of a floating facility or else return to the nearest port, and this does extend the total operating time for conventionally powered vessels in order to accomplish 120

days.

As a matter of fact, it extends it so much in some cases that it is unrealistic because the ice season just doesn't last 9 months of the

year.

So we put this information in a slightly different form. The significant point here is that you see if we limit both the nuclear vessel and the diesel vessel to approximately the same total icebreaking season, one of them showing 166 days and the other one 172 days-this

was to allow the diesel vessel to expend the last of its fuel before withdrawing from the ice-you find that the diesel would only be able to operate for about 77 days rather than those 120 days.

The next slide, please.

We turn these graphs into some figures the most interesting of which are shown in yellow up there. We developed effectiveness figures and they show that if we consider the nuclear as the standard with an effectiveness of 1, that the effectiveness of the diesel ship which is the best of the conventional plants is about two-thirds of that of the same type of vessel powered by nuclear power.

At this point we felt that on the basis of this study we could say that nuclear power was technically feasible, economically competitive, and operationally superior.

We then proceeded with the other two phases which are briefly summarized here. Phase II, the implications of nuclear propulsion, dealt with nuclear ship licensing, manpower implications, shore support and servicing, and finally, program and schedule implications. This report is now being evaluated in-house. Phase III, which is also nearly complete, will be the optimization of a nuclear pressurized water reactor, a diesel plant, and a conventional steamplant.

In addition to these two major areas of investigation, the mission and the propulsion feasibility study, we have carried out about 50 other projects. I think that a discussion of all those projects would take more time than might be fruitful.

These are rather conventional names for design phases. However, we feel that we have used some unusual approaches and we have developed some new and interesting information. The last category listed as R. & T. studies is perhaps the farthest out part of this.

These ancillary icebreaking techniques that are described there are such things as the use of high pressure water jets to cut ice, the use of a pitching plant in the bow of the ship to cause the bow of the ship to jump up and down at a frequency of about one cycle per second and actually nibble it way through the ice.

Another idea was to cause the panels of the ships plating to vibrate. We call that the "coal chute effect" which reduces the static friction. Another idea was that we could use the fore peak of the ship, which is a tank in the very bow of the ship, to a dual advantage. It would enable us to circulate our internal cooling water in case the ice chest became clogged and also heat the bow thereby melting the ice and thereby reducing the coefficient of friction.

We have considered the possibility of some kind of bow auger or screw device to masticate the ice in front of the ship, especially to enable it to get itself free. We are looking for a miracle coating on the hull which be impervious to damage, you only have to put it in once, corrosion resistance, and as slippery as possible.

We feel that we are doomed to something less than complete success there since many other people would like to have the same thing. Mr. EDWARDS. Have you tried the stuff on the Shick razor? Paul Harvey is always talking about this slippery stuff they put on there. Commander RINEHART. I think that is an excellent area for future investigation.

Of course, we did consider something like Teflon but that doesn't look very promising because this material also has to be very resistant

to abrasion. Perhaps we can get somebody with a very tough beard to try it out for us.

This coming month we are going to go out to the Naval Electronics Laboratory in San Diego and conduct some icebreaking experiments with real ice. We have conducted model tests using a certain type of wax which was designed to approximate the strength of ice and we have been able to evaluate the relative effectiveness of various icebreakers including the Wind class.

Incidentally, the Wind class was designed with a bow propellor and still has the propellor stub on some of the ships. We then conducted other tests with this stub removed and the bow faired in and found that there was some improvement. Then we tested the design that we are proposing and found further significant improvement.

Nevertheless, there are difficulties to testing in wax because the scaling is just not what we would like to have it be. So we will conduct these tests in San Diego and hope to develop a method of testing in real ice.

We are making extensive use of computers and we have a program which I was assured yesterday does work that will enable us to perform a very rapid design and evaluation of the characteristics of any proposed ship. Frankly, my Missouri background comes out and I will be very pleased to see that this is true.

Finally there is shown an effort that we are making in the development of a domestic icebreaking system for lakes, rivers, and harbors. Many of the far-out ideas that we have tried and discarded for the polar icebreaker look like they have some good application to domestic icebreakers on the rivers and lakes.

I would now like to show you a rough wooden model of the design with which we intend to enter the preliminary design phase.

There are probably two features that you notice right away. One is the shape of the bow which is considerably different from the shape of the Wind-class bow and indeed from any other icebreaker bow of which we are aware.

You see that the bow overhangs the waterline which is here by a considerable amount and actually clears the water by about 8 feet." This has a very much reduced angle in this area where it first contacts the ice which allows the vessel to hit the ice with much less shock than our present icebreakers do. Now, I mentioned that this is not a combatant ship and we do not have to design to the shock requirements that combatant ships are subjected to.

When you ride one of these things and hit the first chunk of ice it feels like a big shock because nobody in a ship likes to feel a sudden jolt.

Actually, the shock forces are of the order of 1 to 111⁄2 g's. Now, with this bow in the model tests we found that we had shock forces of about one-fourth g. What this means is that less of the energy in the ship goes into crushing the ice just ahead of the ship and more of that energy is converted into potential energy as the ship rides up on the ice thereby getting it farther up on the ice and giving it a better downward force. As you go farther down toward the keel, the angle does increase and as a matter of fact we feel now that we will probably add some kind of a stop, not exactly a vertical projection, but a more vertical projection at the bottom, a sort of forward skeg which will tend to stop the vessel before it actually beaches itself on the ice.

There is a certain amount of danger of beaching and we have seen. this done in most other icebreakers, some kind of stop.

The next most apparent unique feature of this hull form is a tunnelshaped stern, and this is devised to protect the propellers from ice damage.

The Coast Guard was very fortunate several years ago in finding a material for new propellers and since we have been using that material I believe I can say that we have not had any propellor failures. Whereas we used to break and bend a lot of blades, we don't do that any more. What we do is bend the shafts instead.

I don't know that we have made a good trade there or not but we know we have good propellers now. There are still advantages to keeping that ice out of the screws. Our propulsion test, however, has shown that we do have a hull that has more resistance than we would like, obviously due to the fact that we have restricted the flow of the water to the propellers. We keep the ice out but we keep the water out a little too much also. Future refinements of this set of hull lines will probably result in a softening of the buttock lines around the stern.

It is a three-screw vessel. The screws are approximately 16 to 17 feet in diameter, each carrying about 12,000 horsepower. Another feature which may not be so apparent to many of you because of your view is the fact that the sides are straight. They are inclined, but they are straight rather than rounded like the traditional icebreaker hull. I think the idea of the rounded hull was to protect the ship from being crushed in the ice. I am not sure that that wasn't originated on the famous wooden polar vessel Fram.

We feel that this probaby is not necessary and if we have the straight sides that we do have there and also a hard bilge which results we will do two things. We will keep the ice from getting under the ship and that is how it seems to get up into the propellers and we will also improve the sea kindliness of the vessels. These things roll like "sonsof-guns.

Another feature which you cannot see from your position is the fact that the maximum breadth of the ship is up in this area in what we call station 3. (Stations are numbered from zero at the bow to 10 at the stern.) This tends to deflect the ice out away from the ship and also prevents it from getting into the propellers.

Now, I didn't mention another one of our sort of far-out ideas which we hope to put into execution in the next couple of months and that is to hire somebody to get down under the ice and take pictures of this ship as it comes charging through, breaking the ice. We actually have somebody who is volunteering to do this, for a price of course.

Similar pictures have been taken of high-speed naval vessels, not breaking ice but they are going at 30 knots whereas we only want to be going at 3 knots. These pictures are taken from perhaps 50 feet away from the ship. What we would like to see is the flow of ice around the ship to find out how we can modify the hull, get a better hull without actually letting the ice get into the screws.

Another feature which does show is the shape of the stern. The stern does protrude down below the waterline. A problem that we have with conventional icebreakers is that when you back down, you really subject your screws to the greatest chance of damage because the ice is pulled down into the propellers. We have designed a stern which