I'm not sure about the first and second "s"es, but the third is an "ß" (es and zet) that is still used for a sharp s sound following a long vowel... it's still in use, for example in "Straße" (street). The second "t" is a "tz" which is also atill in use in words like Katze (cat).

An open source version of the game "transport tycoon deluxe". A really cool game

Everything on the channel "How to basic" is hilarious...