Towing a ship off a grounding

I am hoping you can help me make sense of this posting. My father was on the SS Cuzco when it was grounded on Lempa Shoals off the coast of El Salvador in 1935. He describes the battle to free the ship, which took place over a 10 day period. On one day he wrote the following:

“The ground tackle was rigged to #3 port Sampson post and a strain was taken. The rig used the Sampson post to haul against and led forward to the cable which payed out through the bow port on the port side. It was rigged so that #2 port winch took the pull through a set of 4 streeva blocks and two match blocks. A fleet ran the length of the forward well deck which made the second ground tackle forward. One ground anchor is equal to four tugs and by nightfall we would have three out forward as well as the two tugs making a total strain equal to 14 tugs forward and 4 aft, due to the gear rigged there, equal to 18 in total. Part of the hull was in 3 to 5 feet of sand though and it would take tremendous power to move us at all.”

I don’t understand the meaning of “streeva blocks” and “match blocks.” “Streeva” may be misspelled.
Can you shed any light on the meaning of these terms?

Thank you very much.

He may have written “sheaves” or “streaming” or “reeving” and “snatch blocks.”

Thank you Steamer! Looking back over his pencilled notes, I think that what he meant was “4 sheave blocks and two snatch blocks”.
Thank you very much for your help!