The bottlenecks

STANDING on the dock at Berth 11 in the Kenyan port of Mombassa, beside the grain-carrying freighter Atlantic Confidence, a stocky official grinned as he promised:

''We'll have this ship unloaded in five to six days.''

Much depends on whether he can keep his word, and keep on keeping it.

A long line of ships is heading toward strategic Mombassa, the only major deep-water port between Durban and Port Said, bringing corn, wheat, vegetable oil, and other urgent supplies to help relieve severe drought not only in Kenya, but in land-locked Rwanda, Burundi, Uganda, and in northern Zaire.

Almost 900,000 tons of grain are due to pour into Mombassa between September this year and the end of April next year. Some 501,058 metric tons for drought relief is either donated or sold on easy terms. The rest is bought commercially.

The projected United States share of the drought-aid wheat and maize: 222,458 tons. A Kenyan commercial purchase of 380,000 tons of yellow maize from Thailand is also unloading here. It is in bags, but US wheat is in bulk because bagging in the West is expensive.

Compared to other African ports, Mombassa is a marvel. It has 16 deep, accessible, sheltered berths. Assab, one of Ethiopia's two main ports on the Red Sea, has only six, shallower, ones.

Yet. . . . Emergency aid is only as good as the speed and regularity with which it reaches the starving. Too much and it swamps trucks and railroads. Too little and it cannot meet the need.

Western officials are watching even Mombassa carefully. Assab is a major worry, and may get worse. Officials don't doubt that Kenya can unload the incoming ships eventually: Kenya is much better organized, and has many more trucks and railroad cars, than poorer, undeveloped, Marxist Ethiopia.

Yet concern persists about ships bunching up, and tonnage due for unloading one month, being pushed back to the next, month after month. ''The port will be stretched, no doubt about that,'' says a private Kenyan businessman.

So far, some 6,000 tons a day have been unloaded in November - against predictions that only 4,000 tons a day could be handled by Mombassa.

Rain (which stops work while grain is hastily covered), vacations, and other factors all slow down the work.

Bottlenecks are already obvious in Assab, while, ironically, the nearby ports of Massawa and Djibouti are under-used. This correspondent was denied permission to travel to Assab, presumably because Addis Abbaba is sensitive to its shortcomings.

A five-member working group of donor nations in Addis made some scathing criticisms of Assab in early November: insufficient machinery, poor labor practices, bad port layout, a lack of spare parts, not enough storage, far too few trucks, and little coordination between those who unload grain and those who transport it.

Emergency grain shipments are also coinciding with large annual deliveries of fertilizer and commercial food imports into Assab, which will further tax the limited number of trucks.

When Terry Page, a senior UN World Food Program official, visited Assab in late September, he found no grain vessels unloading. Port authorities were using a first-come-first-served rule rather than giving priority to grain ships. The unloading rate for grain was 1,000-1,500 tons a day, well below Asian standards.

Giant vacuum-cleaner machines called Vac-U-Vators, in short supply, were being used to unload grain from trucks instead of siphoning grain out of ship holds. Trucks were being filled at dockside by slower ''grabbers'' - mechanical shovels swung by cranes.

Mr. Page has led an effort to rent more Vac-U-Vators (which sell for about $ 100,000 each), fly them to Assab, and train workers to use them. Even then, the shortage of trucks is so bad that Hercules and other transport planes from half a dozen nations had to begin flying grain from Assab to Axum, Makele, and other distribution points.

In Zimbabwe, where as many as 2 million of the nation's 8 million people are affected by drought, and in more seriously hit Mozambique, relief agencies are desperate for more trucks.

The US has just provided funds for 23 trucks for Mozambique - to be bought, ironically, in neighboring Zimbabwe, which lacks the foreign exchange to buy more trucks itself.

''We need 32 trucks but we only have 13,'' says Rashi Chiwani who coordinates private relief efforts in Harare.

Tomorrow: Meeting the Challenge