This is a pattern that was first seen by the West in the Korean war. The Chinese "volunteers" supplied themselves and reinforced themselves at night over routes and trails dominated in the daytime by United States air power. The same practice is being repeated on a vast scale in North Vietnam.

VISITORS MOVE AT NIGHT

The sight must be seen to be appreciated. This correspondent several times was taken out of Hanoi by car either after nightfall or in the early morning hours before dawn. Because of the bombing, the North Vietnamese prefer to move their visitors from point to point under shelter of darkness.

Only during the weekend truce periods over Christmas and New Year's did this correspondent travel over highways in daylight except for brief visits into the countryside outside Hanoi. Even on trips into the Hanoi countryside a few miles beyond the city, the precaution was taken to cover the car, a Soviet Volga, with camouflage net into which branches and leaves were stuck.

It is safe to say that not one vehicle moves on North Vietnamese roads without leafy camouflage on its roof. Trucks are painted olive drab or splashed with camouflage. The same is true of the buses that carry people through the countryside, and of the miniature trains that chug across the rice delta. They are all coal burners, and the engines, freight cars and dilapidated coaches are daubed in gray and dirty brown camouflage.

STREET LIGHTS AT MINIMUM

Hanoi is not blacked out at night, but street lighting is held to a minimum to conserve power, giving an eerie aspect to nighttime travel. The streets become archways of big shade trees with tiny lights burning vaguely in the distance. Outside Hanoi and its suburbs strict blackout precautions are taken. There are no lights whatever showing in villages although occasionally one catches a glimpse of a glowing cookfire in a thatched house or a tiny candle flickering in a window. From dusk to dawn the countryside is dominated by velvet black shadows vaguely illuminated by the stars or, on one trip, by a silver moon that cast a baleful glow over endless rice paddies and clumps of bananas and palms. Along the highways, columns of trucks, bicycle caravans, men and women with their carrying poles move quietly and endlessly. Alongside the main highways, rail lines usually run, and occasional trains can be heard and then dimly seen moving along in the darkness.

The flow of traffic seems shapeless, but it is carefully organized, planned and controlled. There are sentries at the outskirts of the city who control all movement in and out, both by day and by night.

DETOURS ARE EFFICIENT

Guards emerge from roadside sentry boxes, examine passes and then direct caravans onward. They are not only security guards, but traffic officers.

American bombing daily knocks out segments of road, disables bridges or destroys them, makes detours and diversions of traffic necessary if the flow of men and supplies is to be maintained. Convoys move along detours in a brisk and efficient manner. Road blocks are set up at diversion points and traffic is diverted by roundabouts to a point beyond the blockage.

Not infrequently, traffic streams are split, with southward traffic following one route and northward movement coming along a different route. Sometimes detours may lengthen the route by as much as 10 miles, but they seem to provide no really serious handicap to movement.

PONTOON SYSTEM DEPICTED

American bombers concentrate their attention on bridges, which are numerous in the delta area where highways cross canal after canal and many tributaries of the Red River. Many bridges have been knocked out, some as often as four times. But repair crews work constantly to put them back in order.

Since bridges are generally not very long and of relatively light construction, this is done with a speed surprising to an American who is familiar with painstaking construction tasks on United States highways where bridge building or repair may require many months.

At any given moment a large number of bridges on highways leading south from Hanoi may be out of service. However, this does not halt the traffic flow. The

North Vietnamese have the best pontoon bridge system this correspondent has ever seen. It is one that beats the British Bailey bridge system of World War II all hollow.

Alongside every bridge that this correspondent crossed, there were materials available for at least one or two pontoons to be constructed and put into use in an hour's time. The pontoons are made of canal boats lashed together, and the roadway is formed of loose bamboo poles of timbers laid across.

This correspondent crossed dozens of these bridges and watched heavy truck traffic move across them with no more problem than the thunderous reverberation of the loose bamboo roadbed.

Even if the pontoons are destroyed daily, they can be replaced promptly with indigenous materials that cost virtually nothing but the manpower required for assembly and transport.

The efficiency of the pontoons raised the question why the North Vietnamese also employed so much manpower to repair conventional bridges along the highways. There may be a psychological factor involved since the pontoons seem to equal conventional bridges in weight capacity and certainly provide a minimum maintenance problem.

RAILROADS AN OBVIOUS TARGET

The same question arises concerning North Vietnam's railroads. This correspondent did not inspect railroads north of Hanoi since all his trips were southward across the delta. However, according to foreigners who have seen the railroad to the north, in the direction of China, there is not much difference between the bombing destruction and repair program in the north and south.

An enormous effort is expended by the Government to keep the railroads workThey offer a gleaming target for attack, impossible to camouflage, easy to And they are being hit.

ing.

hit.

Bomb damage and craters pepper the railroad mile after mile, thickening in the vicinity of bridges and villages. Life alongside the railroad would seem to be one of the greatest hazards in North Vietnam. As bombers come in to attack the track, there is inevitable damage to civilian habitations along the rail lines and for a substantial distance away from the rail lines. This is particularly true around rail sidings.

North Vietnam's railroad is a single-track affair. Sidings are therefore necessary to permit trains to pass each other. Bombing of such sidings has been devastating to adjoining villages like Phuly, which, for all practical purposes, has been removed from the map by American bombing.

MINIATURE ROLLING STOCK

The North Vietnam railroad is not to be compared with an American railroad. It uses what seem to an American to be miniature locomotives and freight cars. The total amount of rolling stock isn't known to this reporter, but it would be surprising if it totaled as much as the Erie-Lackawanna Railroad has in its truncated New York commuter service.

Unless there is a factor in the situation that escapes observation, the total tonnage moved by railroad must be a small part of the freight moved by truck or by bicycle or by carrying poles.

Nonetheless the North Vietnamese authorities and the United States Air Force seem agreed that the railroad is vital to the war. It is a principal target of United States attacks and the North Vietnamese exert an enormous effort to keep the railroad going, and with remarkable success.

They keep it running by placing alongside it, mile after mile, enough rail metal. ballast, ties and bridge construction equipment to rebuild the railroad several times over. Rail building materials litter the landscape of North Vietnam. It would be difficult to estimate the total volume of rails that are on hand, as well as angle iron, steel rods, wire for reinforcement, ties and processed ballast. As far as the labor force is concerned, it is available in the countryside and has often been seen by foreign residents rushing into action.

ENDLESS TUG OF WAR

Labor is thrown into the task in such numbers that even serious breaches of the railroad are repaired in times that seem remarkable to Western observers. Trucks and earth-moving equipment are kept on hand, scattered and dispersed, so that they cannot be wiped out by lucky bomb hits. It was the opinion of this

observer that the tug of war between the air force and North Vietnam for maintenance of the railroad could go on indefinitely. The only question was whether the effort was worth it, whether the North Vietnamese might not more economically expend their labor on keeping and improving the highway and truck transport system.

However, there is another factor involved here. To maintain truck movement on highways requires constant expenditure of gasoline and oil. Oil storage depots at Haiphong have been successfully taken out of operation by United States air attacks. The capacity of North Vietnam to store oil and gasoline thus has been considerably reduced.

The country is dependent on a steady renewal of supplies by freighter and tanker through Haiphong and probably by tank cars on the railroad coming from China.

The railroad runs on coal and probably could run on wood as well. North Vietnam produces its own coal in ample supply from mines in the northeast so that the railroad may provide a guarantee of a heavy freight route in the event that gasoline and oil stocks are interdicted by the United States.

If the railroad is not being maintained as an alternative to truck movement, then the only explanation for the enormous expenditure of the labor force and materials would lie in reasons of morale and prestige. These are not unimportant considerations in a small country that has been heavily attacked and in which there is a common pride in keeping the war effort up against a powerful opponent.

From this standpoint the sight of trains continuing to move along the tracks through the dusk, rails being relaid and reballasted within hours of a heavy air attack, and bridges being restored by one means or another within days must bolster the morale of ordinary North Vietnamese.

MANPOWER PLENTIFUL

It is apparent after even casual inspection that the American air offensive has cost the North Vietnamese heavily. It compels them to commit manpower that otherwise would be available to reinforce the armed services, build up factory production, lift agricultural output or simply convey supplies to the south.

Now hundreds of thousands of man-hours are needed to maintain supply routes. This burdens North Vietnam's war effort substantially. But, at the same time, there is no sign that the task of maintaining supply routes southward is beyond the country's capacity.

Manpower is still plentiful and this kind of task is one with which the North Vietnamese are familiar and have in effect lived for many years.

The investment of manpower in the movement of supplies has been a basic part of North Vietnamese strategy and tactics from earliest times. For example, in setting a trap for the French at Dienbienphu in 1953 and 1954, the North Vietnamese moved in from China, largely by human power, heavy artillery and munitions that enabled them to outgun the French.

They had to move all the rice to feed their forces about 1,000 miles from Yunnan. Every grain of rice moved either on carrying poles or on bicycles. It is estimated that only 10 per cent of the rice eventually reached the encampments of the hills around Dienbienphu. But it was enough for the troops, accustomed to tighten their belts and carry on.

The North Vietnamese undoubtedly will grow leaner and thinner if the war of attrition goes on. But this has been their history for so many years that it is questionable whether it will produce the effect that this policy is designed to produce—a willingness on Hanoi's part to negotiate peace.

SHORTAGES FREQUENT

The effects of the war on the populace are noticeable to foreign residents of Hanoi. They say that the standard of living has gone down in the past year, that clothing is shabbier and harder to come by, that the diet is harsher. This is confirmed by the North Vietnamese themselves.

One of them said: "You should see us in peacetime conditions. We aren't very good-looking now. We are thin and worn and the girls aren't so pretty." But the North Vietnam living standard has never been high. It probably was not as low under the French as the Vietnamese now contend. They insist that under the French many people in the north had nothing more than rags for

clothing and one of the regime's bragged-of achievements is that now everyone in the north has a dress or trousers and a shirt to wear.

Still, shortages are frequent. During the fortnight this correspondent was in Hanoi, matches were not to be had in stores. Not long previously cigarettes were scarce for several weeks. Soap has been hard to get. Salt supplies have not always been available in villages.

Meat is scarce for ordinary Vietnamese and chickens are expensive in village markets-about 8 dongs a kilogram (2.2 pounds). The dong is officially valued at 3.53 to the dollar. The average wage is 70 to 80 dongs a month. Women get

a ration of five or six yards of cotton cloth a year and men the equivalent in cloth or clothing.

Long-time Hanoi residents say these shortages are reflected in the shabbier appearance of residents compared with the period before the bombing began. The city itself is badly run down. Few buildings have been painted in recent years and bombed wreckage remains, with no effort to repair. Cars are worn and gasoline makes them spit and cough.

NO EFFECT IS SEEN

But none of this seems likely to have much effect on North Vietnam's war effort. In villages, where houses and huts are bombed, they usually are repaired quickly if the damage is not too serious, or new houses are built. Houses are mostly of simple clay and wattle construction with thatched roofs. If residents survive the attack, they can rebuild houses with their neighbors' help in a short time.

It is different with more substantial buildings. In most villages and towns that this correspondent saw, bigger buildings tended to suffer more damage. Residents contended that bigger buildings were more frequently singled out for bombing attacks. In many towns most bigger buildings had suffered damage. Brick structures, whether damaged or not, had simply been abandoned and residences, offices, schools, artisan cooperatives and hospitals had been dispersed into small one-room huts and houses.

FACILITIES ARE DISPERSED

The dispersal puts an economic burden on North Vietnam and almost anything that is now hit by a United States bomb is likely to be an institution of some kind. This is particularly true in the environs of Hanoi.

In expecting heavy bombing of Hanoi, the authorities have scattered offices, schools, factories and almost everything moveable into villages and towns nearby. Since the Air Force has been paying more attention to the environs of Hanoi than to the city itself, substantial casualties have been caused in evacuated schools. The authorities admit this but say they are caught in a dilemma. If the United States starts a saturation attack on Hanoi, they do not wish to expose the people to mass casualties. They prefer to risk scattered casualties resulting from the evacuation.

The net conclusion of many foreign residents of Hanoi is that while American bombing has damaged North Vietnam severely, causing heavy material and human losses and compelling the Government to invest men and material in neutralizing the attack, it is not likely to provide a decisive factor in maintaining the fight in the south or in compelling Hanoi to capitulate.

Foreigners in Hanoi believe the North Vietnamese when they say they are prepared to sacrifice Hanoi, Haiphong, all their cities and towns, rather than yield under American bomb power.

BOMB CONTROVERSY: VIEW FROM THE GROUND-U.S. SAYS ITS TARGETS ARE ALL MILITARY-HANOI DISSENTS

Following is the third of a series of articles by an assistant managing editor of The New York Times summing up observations on his recent visit to North Vietnam.

(By Harrison E. Salisbury)

HONG KONG, Jan. 11.-The most controversial subject concerning military operations in Vietnam is the United States air bombardment, what the United States is seeking to bomb and what the bombs are hitting.

President Johnson has stated American policy in simple terms. He said that the United States was bombing "steel and concrete" and that he was convinced American pilots were carrying out those orders.

The North Vietnamese contend that the United States is pursuing a deliberate policy of terror bombing, with civilian population and nonmilitary objectives as the target.

Wherein lies the truth? After two weeks of painstaking observation and inquiry on the ground in North Vietnam, this correspondent can report only what he saw and what he heard. Many bombs have fallen on targets that unquestionably are military objectives by any definition. Many bombs have also fallen on targets that are not military targets.

What are the military targets that have evidently been bombed? Foremost are the railroad and the railroad bridges running south across the delta from Hanoi and Haiphong. Foreigners in Hanoi report that the railroad north from Hanoi has also been bombed.

Highways running south and bridges along them have been bombed.

Other targets that this correspondent saw and that had been bombed are railroad sidings, antiaircraft gun sites, the Yenvien railroad yards and the socalled Vandien truck park in the Hanoi metropolitan area, several factories, and several buildings that probably served as military barracks.

In addition, Westerners in Hanoi confirmed that oil storage depots in Haiphong were destroyed in the initial United States attack last June 29.

What are the nonmilitary targets that can be seen to have been bombed? They are several residence areas in Hanoi, substantial areas of mixed housing, small shops and miscellaneous buildings in the suburbs of Gialam, Yenvien and Vandien in the Hanoi metropolitan area, several schools in the Hanoi area, villages and hamlets along highways leading south from Hanoi, large areas of housing and shops in towns like Namdinh and Ninhbinh and in the Phatdiem village complex, and a variety of other objectives, including cemeteries.

MISSILES MISFIRED

When Hanoi officials first reported that American bombs and aircraft-fired rockets had struck the city Dec. 13 and 14, United States officials contended that the damage might have been caused by the misfiring of one of the surface-to-air missiles used by the North Vietnamese to protect Hanoi against American air attack.

Later one American airman who had participated in the attack said he had seen two missiles misfire and had observed the missiles hitting the earth in open areas outside Hanoi.

The possibility of misfiring of missiles is not excluded by this correspondent. But no person with whom he talked in Hanoi, either official or unofficial, either North Vietnamese or foreign, either Western or Eastern, believes that the major areas of damage in the attacks of Dec. 13 and 14 resulted from missiles. Rightly or wrongly the opinion in Hanoi is that the damage was caused by the Americans, not the North Vietnamese.

THE ISSUE OF THE DIKES

There is also the question of dikes and levees. Are they legitimate military targets? That seems to be a matter of definition. If they were to be destroyed, the richest areas of North Vietnam would be devastated with a heavy loss of life. The United States contends that the dikes have never been cleared as targets and in fact have never been bombed.

However, North Vietnamese officials charge that the levees have been attacked repeatedly, particularly last summer during the high-water stage, when a breach in the dike system could have been catastrophic.

This correspondent has seen craters in and around dikes where bombs have fallen. Other Westerners have seen bomb hits on dikes and strings of craters along a line of levees.

Whatever the reason for the bombs falling on dikes, the effect was the same as if the bombing had been intentional. The North Vietnamese authorities regard the attacks with such seriousness that they have mobilized thousands of laborers to throw up auxiliary walls and dikes to hold back the water if the main system is breached.

CARRIER BRIEFINGS REPORTED

It is easy to establish that widespread harm has been done to civilian housing and nonmilitary institutions and that civilian casualties have been extensive