In the method of tube boring of soil investigation, the following is essential :

• a tube of about 2 metres length and 20 cm diameter with a cutting edge
• a flap valve at the bottom of tube is provided to extract the soil sample
• the tube is raised and lowered by 4 thick rope moving over a pulley suspended on a tripod stand
• the tube is dropped to fall under gravity in side a metalic casing pipe which is driven as the depth of excavation proceeds.
• all the above.