Sledeći delovi nisu na crtežima, ubacuju se u toku rada. Radi se o formiranju tunela, postoje otvori izmedju delova O i dela P, zatvaraju se sa trouglovima ( formiraju se stranice levog i desnog tunela ). Označeno na slici sa crvenim strelicama. Takodje postoje otvori ( levo i desno ) izmedju delova O, D, H i F - to je na slici zaokruženo žutom bojom, koji se zatvaraju delom koji je na sledećoj slici ( trapez čija je donja ivica oborena na 45*, ta ivica naleže na O )
The following parts are not on the drawings, they are inserted during the building process; They are necessary for tunnel forming. There are openings between the O parts and part P, they should be closed with triangle shape parts (they forming on this way the sides of the left and right tunnel). That is marked on the picture with red arrows. There are also openings (left and right ) between the parts O, D, H and F – they are on the picture circled with yellow. That openings should be closed with a part what is shown on the next picture (a trapezoid, whose bottom edge is lowered to 45 *, that edge comes on the part O)