by Joe Poyer
Jensen pulled the tripod-mounted blackboard around and quickly sketched the outline of the strait – essentially a narrow channel running southeast to northwest and widening gradually at the two-hundred-mile point until it was nearly two hundred miles wide at the five-hundred-mile extreme length. At the entrance to the strait, he drew in the island of Singapore and the Malay Peninsula, and directly south, dotted a group of islands that filled the entrance, leaving only narrow channels. With a series of dots he indicated the major concentration of the various fleets in and around the strait. To the south, he drew the ragged outline of the coast of Sumatra and its islanded shore.
'Now, gentlemen,' he went on, turning to face the others, 'you are all pretty much familiar with this area by now. As you can see, the Vietnamese research station and the bomb –are here in the center of these islands at the head of the strait. These islands are volcanic in origin and their peaks are quite lofty, rising some eight and nine thousand feet. These two islands are our two containment islands.By that,I mean that these two islands will absorb a good portion of the blast and shock wave, thereby protecting the two mainlands from bomb damage per se. The smaller islands forming the apex of the triangle will seal off the South China Sea from both the bomb blast and the resulting tidal wave. Now, because the wind currents in this area are northerly, and quite strong at high altitudes, the majority of fallout in the form of radioactive rain will be carried north across Singapore and southern Malaya state.
`The channel of the Malaccan strait is four to five hundred miles long – only two hundred of which are important to us. These two hundred miles are the narrows, the area where guerrilla infiltration is the heaviest and where the Malaysian and Indonesian patrols are concentrated. I don't think anyone here will dispute the fact that it is only the presence of these fleets that prevents a major infiltration south into Sumatra as well as north into the southerly portions of Malaya.' Jensen beamed around the room. 'As you remember, prior to the Communist coup which failed a few years ago, the Indonesians were ready to mount an all-out offensive on both the Malay Peninsula and the Malaysian-held half of Borneo. A foothold in Sumatra would be an extreme danger to both nations.
`But, to continue, the strait is relatively shallow – roughly twenty-five fathoms – and only about thirty miles wide.
'If, gentlemen, this five-megaton bomb is exploded in its present location, a tidal wave will sweep up this channel, carrying everything with it to destruction. If you don't believe me, and I see a great number of you don't, it can be proven with a few simple calculations. Permit me?
`The shallow underwater bursts,' Jensen said, juggling the stub of chalk, 'of the Bikini "
Baker" tests in the late 1940s, give us a set of data from which we may extrapolate. Our problem is first to determine pressure variance between open-water explosions and open-channel – such as the strait – explosions at equal distances. We do this as the Bikini tests were conducted in open water, and therefore, the data we have is based on open-water explosions.
'If we assume a radius of one hundred miles for easy calculation, and draw a rough sketch of the blast area:
we can find the amount of water moved above the line A—A by the simple relationship: Q equals AV, where Q is the flowrate (in miles 3/hr. in this case), A is the area of the wavefront at a distance which I'll call R, and V is the speed at which the wave-front is moving. If we put them all together in an equation and solve it, we get: Q =0.5(27* R)V = RV
100 * V
assuming, of course, that depth equals unity.
`Now, if we picture the Strait of Malacca as looking like this: we can assume that the arc length of the wavefront at one hundred miles will be just a bit greater than thirty miles; say, closer to forty, since any wave produced will overlap the land. If so, once again we can find the amount of water moved, but in this case, just the amount up the strait, by using the relationship Q =AV again, but adding in the forty-mile wavefront, like this:
Q =AV
=40V
again assuming that depth equals unity.
Now, let's examine this a little. Assuming that there are no flow losses nor any areas where pressures will be equal – equal point pressures, in other words – the amount of water moved by an exploding bomb in the open sea will equal the amount of water moved in a closed channel. Or:
100^V
40V closed
closed 100^
V.... 40
=7.85
`Now, apply Bernoulli's principle: pressure is proportional to the square of the velocity.
Or in this case, we find that the pressure will be sixty-one and sixty-two hundredths times greater in the channel than in the open sea.
Ìn other words, gentlemen, this all means that the velocity of water moved up that channel will be seven point eighty-five times faster than it would begin the open sea, and further, the pressure behind that wavefront of moving water will be sixty-one point sixty-two times greater in that channel than in the open sea.'
Jensen paused in his whirlwind delivery. 'Stick with me, gentlemen, we've just begun.
And we haven't even come to the bomb yet,' he said with a grin.
Keilty craned closer for a better look. The calculations were just so much Greek to him.
He was a psychologist and had flunked second-year high-school algebra while a freshman in college.
`Do you gentlemen realize the significance of these two equations. They are going to cause a wave, and quite a wave at that, as you will see in a moment. But let's go on.
Based on constants used in the Kutter-Ganquillet formula for open-channel flow: N=0.010 for a smooth surface
N= 0.050 fora natural channel
we can state that the pressure change in the channel will be only one fifth of what we calculated just now, since we have been assuming that the strait's channel had a smooth bottom. So now we have:
AP=61.62/5
=12.32
and because of the bad sea conditions expected tomorrow as well as pressure absorption out into the open sea, we shall assume a maximum dispersion of four and still get: P P=12.32/4
=3.08
which simply indicates that any bomb exploded in a thirtymile-wide channel would effect a water-pressure force equivalent to that produced by a bomb at least three times its size, exploded in open water.
Jensen paused again, this time waiting for the conclusions to sink in. Keilty, who had only a layman's hazy idea of the sizes and potential power of thermonuclear weapons, was puzzled at the deeply shocked silence and then the flurry of activity that followed.
Common sense told him that any bomb exploded in a confined area would do more damage than one exploded in
open surroundings. He did not realize, however, the magnitude, size, and power involved. Slide rules were hurriedly consulted and notes and equations began to fill scratch pads, but Jensen did not wait. He went on at breakneck speed.
'Now, gentlemen, comes the real corker. We know that a five-megaton bomb will be equivalent to a fifteen-megaton bomb in this situation, a seven to a twenty-one, ten to thirty, twelve to thirty-six, fifteen to a forty-five, et cetera. We can extrapolate from a simple chart; I believe it is figure six point seven nine from the Effects of Nuclear Weapons, an Atomic Energy Commission publication – I forgot to write it down earlier,'
he admitted somewhat sheepishly. 'Anyway, figuring our five-megaton bomb to equal fifteen megatons – which is fifteen thousand kilotons for ease in calculation – we can easily extrapolate from known graphs.
'Since the chart is scaled to eighty-five feet, we must rescale the graph: Scale height = 180 / (15,000) 3'
=16.26 ft.
According to this graph, the scale factor will be:
Scale factor= .036(16.26) = .585
and the resultant wave height:
Wave height = .585(15,000)' =71.7 ft.
All of which gives us a wave that even at the two-hundredmile mark from surface zero will be seventy-one feet high for a five-megaton bomb. The wave
height from this bomb at thirty miles from surface zero can be derived:
Scale factor= .18(16.26) = 2.93 ft.
Again the wave height would be:
Wave height =2.93(15,000)% =370 ft.
which means that this wave will be three hundred and seventy feet high thirty miles from the explosion site or surface zero!'
By now, the gathered military and government officials had received so many shocks that they merely greeted the result that they had all been afraid to admit was the only answer, with silence.
'A last thought, gentlemen,' Jensen said, rubbing off the blackboard. He turned to face the assembled wardroom. 'The force of this wave along its thirty- to forty-mile-wide front will be on the order of one hundred billion pounds! The coast of Malaya bordering on the strait is low-lying flatlands, while the coast of Sumatra is fairly high, shading up to coastal mountain ranges. A wave of this size and with this much power behind it in a channel as narrow as Malacca will most surely be a breaker type of wave, and not a long swell.
'If you are at all familiar with tidal waves, you know that no matter how great the wave or the force it packs, it is a long swell in the open ocean over which ships ride, hardly knowing they have been caught in a tidal wave. However, when these tidal waves approach shallows and bays or harbors, they become immense breakers. That is the situation we face here.'
Jensen turned quickly to the commander of the Bradley, 'Captain, would you say that you could ride out a fifty-foot wave — a breaker wave — let alone a three-hundred-and-seventy-foot breaker?'
'Well, I don't know,' the captain answered slowly. 'A fifty-foot breaker maybe. But any ship smaller than ours would not stand a chance.
'Exactly, sir, anything smaller would not stand a chance against a wave of this size. And most of your fleet is composed of motor torpedo boats, corvettes, and small minesweepers —and destroyers such as yourselves. Thank you, gentlemen.' And he sat down. A complete and dead silence answered the end of Jensen's lecture.
From where he sat, Keilty spoke up again. 'How about that? With one fell swoop, the Vietnamese are going to wipe out not only your naval squadrons but shore-based installations as well. With the Malaysian armed forces disorganized and in retreat up the peninsula or engaged in rescue work, the Australians, New Zealanders and the Indonesians helpless because of their parliaments and their own lack of naval craft, the insurgents backed by the Vietnamese are going to come down that peninsula and beat the hell out of whoever is left.'
His voice was heavy with sarcasm as he went on. 'They will close the world's busiest shipping lanes to whoever they want and scare the hell out of the Philippines, Japan, India, Thailand, et cetera.
'That bomb will kill thousands of your troops and sailors, wreak havoc with the Indonesian fleet in the strait and the
Australasian fleet in Singapore and throw you all the hell out of the Indo-China peninsula.'
Keilty's voice was calm but his face was angry and red. Everyone in the steaming wardroom was quiet, listening to him expound the fears they were loath to admit.
'Perhaps you will bomb,' he continued, his voice beginning to rise. 'The U.S. won't be able to give you much help. We are overextended in this area now since Congress'
cutback last year.
'What will you do?' he challenged the British Foreign Secretary. 'Use nuclear bombs on Vietnam? Invade? Not likely. It's been tried before.
'Can't you people realize that this is big, not just an isolated incident, but part of a well-planned scheme to kick you people all the hell out of this part of the world. You don't play around with nuclear weapons for kicks, and they know it as well as you.'
'Face it,' Keilty's voice was very cold, 'they have you if that bomb goes off.' He paused for a moment, then went on, 'Your problem is to see that that bomb does not go off. It's as simple as that.'
There was silence for a moment when he finished speaking. Finally, the British Foreign Secretary spoke. 'Thank you, Dr. Keilty. We are well aware of the problems we face here. However, there are certain ramifications, such as incursion on a sovereign nation's territory, world opinion ...'
'Nuts,' Keilty interrupted shortly. 'World opinion be damned. You and the French let yourselves be swayed by world opinion in fifty-six, and as a result, Nasser made laughing stocks out of you.
The American Secretary of Defense coughed and fidgeted. Keilty grinned.
'This time,' he went on, 'you are going to make asses out of yourselves if you continue to sit around down here and let that bomb go off. As for world opinion, the Vietnamese have dug themselves their own grave. This research station has received a fair amount of publicity in the past few months. So turn it against them. Pull a surprise raid and disarm the bomb before they can set it off.'
A signalman came in hurriedly, saluted, and handed a flimsy to the H.M.S. Bradley's captain. He read it through and looked up solemnly.
'Gentlemen, there seems to be a Vietnamese warship on
course for the station. Satellite reports indicate that she left Saigon earlier today. Our intelligence believes the ship to be a destroyer delivering the trigger device and that it will take the people off the research station. Their estimated time of arrival is nine hundred hours tomorrow.'
Ànd,' Keilty interrupted, 'you have a heavily armed destroyer, a hundred marines, and two MTBs. And your last chance.' He stood up abruptly and went on deck, pausing to speak briefly with Charlie in his tank near the bow where they were preparing to take him below. After a few minutes he left and climbed forward over the winch until he was leaning against the railing at the bow of the ship. He watched the curving knife edge of the prow slash methodically into the marching procession of whitecaps, the water curling away to either side of the bow, half as high as the deck, in black sheets. The lifting crash of the bow against the waves set the entire ship to shuddering under the sharp concussive shocks. He stayed there watching, wondering what they were deciding below, feeling that he had made a fool of himself with his outbursts.
He turned and clambered back to Charlie's tank, hoping that at least if they didn't have sense enough to put a stop to the Vietnamese foolishness, they would have brains enough to dear out of the strait as fast as possible.
CHAPTER SIX
When Keilty returned to the wardroom an hour later, he found himself stopped at the hatch by a marine guard with a Sten gun, fully cocked.
`Sorry, sir, but ye dinna go in there.
Keilty looked the brawny Scotsman up and down, noticing the set and intelligent face, and decided against making a fuss.
'Do me a favor,' he said. 'Get Admiral Rawingson out here. He'll get me a pass or whatever the devil I need.'
The marine hesitated a moment, then turned and spoke briefly into the intercom. The hatch opened seconds later.
`There you are,' Rawingson growled. 'Wondered where you got to.' He put a hand on Keilty's shoulder and pulled him in, saying to the guard, 'It's all right, Corporal, we need him in here.'
As Keilty entered, he noticed that now, not only was the cooling system prevailing against the pre-monsoon heat, but cooler heads prevailed also. The men were grouped around a large map tacked on the display board at the end of the room. There was no more angry discussion, nor were insults or imprecations being tossed back and forth.
Instead, they were listening closely to the American Secretary of Defense as he carefully went through the various alternatives. Keilty moved halfway into the room and perched on a table. He pulled a cigarette from the pack in his shirt pocket and thumbed an old, worn Zippo to light it, then settled down to listen. Rawingson sat down on the bench below him and bummed a cigarette, then turned his attention also to the map.
The map was a larger version of the one Rawingson had shown him two days before.
Over it, a sheet of acetate was taped, with grease-pencil markings indicating, first of all, the location of the bomb, then the currents in the strait and the surrounding area.
The Bradley's meteorological off
icer had drawn in red the wind currents in the vicinity.
A black area shaped like a many-pointed star was located in the Celebes marking the spawning grounds of the summer monsoon. Black arrows also extended northwestward across the Indonesian islands and into the Bay of Bengal to the west of Burma. A series of numbers that Keilty
could not read from where he sat probably indicated expected times of arrival along the monsoon path.
Directly north, over southern China and North Vietnam and extending west to Thailand, the limits of a high-pressure area were drawn in green. This presumably was forcing the monsoon to approach more slowly than usual.
'It is our feeling,' the American Secretary of Defense was saying, 'that they have been planning this attack which they call "Operation Malacca" for quite some time now. They have been extremely fortunate that the weather has furnished such a large high-pressure front.' He indicated the area from the China Sea to Thailand, 'It is producing fair and very dry weather in the North and very shortly will turn the South into a sea of mud and rain.
This will aid their movements down the Peninsula, while at the same time it will hamper Allied forces in Malaya if we are forced to evacuate from Kuala Lumpur and Singapore.
'The weather will certainly not hamper the insurgents in crossing the strait to Malaya, Singapore, and Borneo. For one thing, we will have lost almost our total straits fleet, so they will have no trouble from that quarter.
'By crossing,' he continued, 'in small craft under the cover of wind and low rain clouds, our bombing will be reduced to almost complete uselessness. Personally, I don't think they will make any trouble south into India. Since the Red Chinese lost their influence in Vietnam, the Soviets have been counting on India to contain China from that direction.'
`What happens,' Keilty asked suddenly, 'if the Indonesian Conununist Party joins with the Malaysian Communists in a drive across Sumatra as well as up the Malay Peninsula?
They just might figure it is time to act again, this time backed by the Vietnamese.'
The Secretary gave him a long, sad look. 'Your point is well taken, Dr. Keilty. It is just one more of the many possible alternatives to consider.' He was speaking now to the representative of the Indonesian army who shifted uncomfortably.