Racket 164159 bytes
(let((d display))(let p((n 2)(x 0)(t 0)(d display))(when(> x 69)(d"\n")(set! x 0))(cond[(> t 699)
(d"\n")][(> n 2)(d"|")(p 0(+ 1 x)(+ 1 t)d)][(d"_")(p(+ 1 n)(+ 1 x)(+ 1 t)d)])))
Ungolfed:
(define (f)
(let ((d display))
(let loop ((n 2) (x 0) (t 0) (d display))
(when (> x 69) (d "\n")
(set! x 0))
(cond
[(> t 699) (d "\n")]
[(> n 2) (d "|")
(loop 0 (+ 1 x) (+ 1 t) d)]
[else (d "_")
(loop (+ 1 n) (+ 1 x) (+ 1 t) d)]
))))
Testing:
(f)
Output:
_|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|
___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|__
_|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|
___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|__
_|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|
___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|__
_|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|
___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|__
_|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|
___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|___|__