Two hundred and fifty Cambridge children residents last Thursday shifted their one year-old campaign against loud trucks on residential streets into high gear when they blocked a two-block stretch of Prospect St, north of Central Square and demonstrated for about one hour.

The residents--members of Human Against Load Trucks (HALT)--ranged in age from sub-teens to septuagenarians. They were joined in their protest by Mayor Barbers Ackermann and Councillor Alfred E. Vellucct.

Halt staged the demonstration to dramatize three demands.

* That Cambridge create and enforce a city-wide noise control ordinance, thus eliminating 30 to 40 per cent of the loudest trucks:

*That heavy trucks be banned from residential streets between 6 p.m. and 8 a.m. on weekdays and all day on weekends, and;

*That Cambridge police enforce existing speed limits and weight restrictions against truck.

The action began at 7:35 p.m. with a rally in a parking lot on the corner of Prospect and Austin Streets. As a series of speakers condemned the trucks for creating noise, pollution, running building foundation and endangering small children , grant tractor-trailers rumbled by in the background.

"These goddamn trucks destroyed the foundation of my home," bellowed Mike Tetrault, who admitted to being in his seventies.

"Trucks should be off these streets--says who, says me," ten year old John Matthews told the gathering. A friend of his chimed in. "Is little kids are the ones that get missed up by the friggin Mack Trucks.