|Section installing pitch, m.||1,75||1,75||1,75||1,75|
|Quantity of hydraulic props in the section, pcs.||2||2||2||2|
|Resistivity of the support, kN/m², not less||700…990||840…980||840…980||1055…1145|
|Section resistance, kN, not less||6700…7300||6950…8150||6950…8150||8160…8865|
|Average ground pressure, MPa, not more||2,05||2,2…2,6||2,2…2,6||2,0|
|Operating pressure, MPa||40||40||40||42,5|
|Section advance pitch, m.||0,63; 0,8||0,8||0,8||0,8|
|Section weight, t.||19,5||22||24||26,5|
The powered support M21 consists of two-props sections with four-chain linking system of the basis with the barrier; the rigid-linked ceiling, equipped with the flap visor with enhanced effort and device for face keeping (from H ≥ 2.5 m). To adjust the section in the seam plane and to protect the workspace under the support against small stuff extension boards and pusher-jack (with or without landside) installed onto one side are used in the section. It is possible to reinstall boards and pusher-jack onto another side, also to manage them independently separately from both sides of the section.
The whole operating range for small and medium seam thickness is offset by a number of sections with an installing pitch 1.75 m. Also, quantity of sections in the longwall and time of their extension are reducing in comparison with the supports 1М21.