American surveyors sometimes used a longer chain of 100 feet ( 30.48 m ) , also of 100 links , known as the `` engineer 's chain '' or `` Ramsden 's chain '' .
American surveyors sometimes used a longer chain of 100 feet ( 30.48 m ) . This is called the `` engineer 's chain '' or `` Ramsden 's chain '' .