(a) The crusher shall produce aggregate at the rate of 75 tons per hour (tph) with the jaws
adjusted to a closed setting of not more than 2 inches.
(b) When the crusher is used as a primary crusher in conjunction with a secondary
30-inch-diameter by 24-inch-width roll crusher, the capacity shall be compatible for
the production of 75 tph of material passing a 1-l/2-inch square screen opening from
the secondary crusher.
188.8.131.52 Quarry rock. The quarry rock shall be diabase or traprock having an average
compressive strength of not less than 32,000 pounds per square inch (psi) when tested in
accordance with ASTM C170, and shall have a percentage of wear not exceeding 20 percent
when tested in accordance with ASTM C131.
3.1.2 Maintainability. All major assemblies and installed attachments shall be accessible for
maintenance and repair utilizing common hand tools and special tools furnished with the crusher.
The replacement and adjustment of components and accessories shall be accomplished with
minimum drainage and minimum disturbance to other components of the crusher. Ease of
maintenance provisions shall incorporate, to the maximum practicable extent, features insuring
operating clearances and facilitating maintenance and servicing operations. Intricate locking
devices and controls with threaded fastenings which can be overtorqued by operators shall not be
used. Covers or plates which must be removed for component adjustment or repair shall be
equipped with heavy-duty quick-disconnect fastenings. Unless otherwise specified herein,
covers, plates, panels and guards which must be removed for adjustment, maintenance, or
component removal shall be held in place by nonremovable studs, washers, lockwashers, and
nuts. Where practicable access shall be provided by a hinged door.
3.2 First article (preproduction model). The contractor shall furnish a crusher for
examination and test within the time frame specified to prove, prior to starting production, that
his production methods and choice of design detail will produce crushers that comply with the
requirements of this specification (see 6.3). Examination and tests shall be those specified
3.3 Initial production. When specified, the contractor shall furnish to the Government one or
more crushers for inspection as specified in 4.4.
3.4 Material. Material shall be as specified herein (see 6.7). Material not specified shall be
selected by the contractor as being compatible with the intended use in accordance with the
engineering standards of the earthmoving and construction equipment industry and as set forth in
the publications of the American Society for Testing and Materials (ASTM), Society of
Automotive Engineers including SAE Handbook (SAE), American Society of Agricultural