the development team worked with severe shortages of technical experience, funds, and equipment. they often worked in hunger as china was in the midst of the great famine. they performed calculations using hand-cranked mechanical computers as the team did not have an electronic computer, and a single ballistics calculation could take more than forty days. the launch site, located at in nanhui county outside shanghai, consisted of a sandbag bunker and a power generator. people at the launch bunker communicated with the tracking sites by relayed shouting or hand signals, and the rocket's liquid fuel tank was pressurised using a bicycle pump.