wide-to-tall.sql

SELECT
  dept_id   AS dept_id
  , 1       AS hours_id
  , hours1  AS hours
FROM
  hours_table t
WHERE
  hours1 IS NOT NULL

UNION ALL

SELECT
  dept_id   AS dept_id
  , 2       AS hours_id
  , hours2  AS hours
FROM
  hours_table t
WHERE
  hours2 IS NOT NULL

/* ... repeat a whole bunch */