Renovating cities of the Old World with New World ideas

The New World is helping the Old.

Beneath headlines of trade wars and policy clashes, the United States is providing ideas to help Britain in four key areas. They range from reviving inner cities to working out the parking and hotels for efficient theme parks.

In each case, British officials are eagerly drawing on US experience.

The American concepts include:

* Bringing to life old and battered inner cities. The British government is using a form of central government incentive grants to private developers based on the federal Urban Development Action grants in the US.

* Transforming huge, disused cotton mills into offices, apartments, warehouses, and factories, just as Maynard, Lowell, Lawrence, Andover, and Springfield have done in Massachusetts.

A six-man delegation from the English northwest and west Yorkshire, which is dotted with once-thriving mills, has just toured Massachusetts and produced a report now in the hands of Prime Minister Margaret Thatcher and her cities minister, Michael Heseltine.

* Reviving desolate shoreline areas in big cities, creating marinas and apartments and shopping centers as Boston, Baltimore, and other East Coast cities have done.

A powerful new quasi-government corporation created by Parliament is hard at work in some of the world's oldest, largest, and most run-down docks in Liverpool. It is drawing in part on US experience.

* Turning waste or reclaimed land into profitable, publicity-generating theme parks on the model of Disney World, Circus World, and Sea World in Orlando, Fla. , and other theme parks up and down the eastern United States.

Sir John Grugeon, an energetic Englishman, has just toured US theme parks for 10 days to mine ideas for the first international garden festival ever staged in Britain, on 250 acres of long-abandoned dock yards in Liverpool, between April and October 1984. The Queen is expected to attend.

Sir John, festival director, expects 3 million visitors. Eighteen countries, ranging from Italy to Japan, have already agreed to create various types of display gardens.

In his US tour, Sir John said he learned the importance of high-quality souvenirs, efficient car parking and transport from parking lots to exhibition sites, strict cleanliness and hygiene, and smiling hotel staffs that put the tourist first.

All four examples came to light during a Monitor visit to Liverpool and Manchester and talks with officials working hard to overcome the blight and decline of inner-city areas.

The pattern is familiar to an American: Major industries, such as the docks and shipping in Liverpool, gradually decline. Downtown streets and services are neglected. People with money move to leafy suburbs. Those who are left live on government payments of various kinds.

One of the key components of the Thatcher government's attack on inner-city blight these days is the Urban Developmet Action Group. The government is offering a total of (STR)70 million ($119 million) to development plans that bring in private money on a matching basis. Every pound of government money must be matched by three from the private sector.

In all, Mr. Heseltine hopes to generate (STR)280 million ($476 million). Initial planning is under way.

Meanwhile, the six-man team from England that examined Massachusetts cotton mill buildings was drawn from Manchester, Wakefield, Preston, Bolton (and included an official from Roubaix in France).

''The group was tremendously impressed at what you are doing over there,'' Manchester Chamber of Commerce president A. M. Toms told the Monitor. ''You've done wonders with your old mills. We can learn a lot from you - especially the way you float state bonds that are tax-free for specific development projects.''

Britain has no equivalent of such bonds at present. The central government plays a much heavier role in providing and controlling funds for local development.

The British delegation was also struck by the way the US generally uses tax concessions rather than relying wholly on Washington grants to stimulate local development.

Along the Liverpool dock area, a trade and tourist mecca in the heyday of transatlantic sea travel, Basil Bean and his Parliament-created Merseyside Development Corporation are pumping out silt and sewage and reviving dockland over 865 acres of Britain's worst urban blight.

''Look what you've done in Boston and Baltimore,'' Mr. Bean said in an interview in offices overlooking the polluted, underdeveloped waters of the Mersey River.

''We can do the same. Our dock buildings are even better than yours. We lack your climate and your eating habits, but we can develop housing and museums and shops and marinas, and boost Liverpool through leisure services just as you have done in the United States.''