Standard Bus Procurement Guidelines - APTAStandards.com

Standard Bus Procurement Guidelines
(11) Heavy Heavy-Duty Diesel Engine (HHDD). Heavy heavy-duty diesel engines have
sleeved cylinder liners, are designed for multiple rebuilds, and a rated horsepower that
generally exceeds 250.
(12) Operator's Eye Range. The 95th-percentile ellipse defined in SAE Recommended
Practice J941, except that the height of the ellipse shall be determined from the seat at its
reference height.
(13) Fireproof. Materials that will not burn or melt at temperatures less than 2,000Ε F.
(14) Fire-Resistant. Materials that have a flame spread index less than 150 as measured in a
radiant panel flame test per ASTM-E 162-75.
(15) Human Dimensions. The human dimensions used in Part 5: Technical Specifications
are defined in SAE Recommended Practice J833.
(16) HIC (Head Injury Criteria). The following equation presents the definition of head injury
criteria:
where:
⎡
⎣
⎢
t
1
− t
1 2
∫
t
t
2
1
⎤
⎦
⎥
2 . 5
( a ) d t ( t 2 − t 1)
a = the resultant acceleration at the center of gravity of the head form
expressed as a multiple of g, the acceleration of gravity.
t1 and t2 = any two points in time during the impact.
(17) Baseline Configuration Bus. The bus described by Part 5: Technical Specifications if
no alternatives are selected. Signing, colors, the destination sign reading list and other
information must be provided by the Procuring Agency in attachments to Part 5:
Technical Specifications.
(18) Alternative. An alternative specification condition to the standard configuration bus.
The Procuring Agency may define alternatives to the standard configuration to satisfy
local operating requirements. Alternatives for the standard configuration will be clearly
identified.
(19) Design Operating Profile. The operating profile for design purposes shall consist of
simulated transit type service. The duty cycle is described in the figure “Transit Coach Duty
Technical Specifications 120 10/18/07