未铺砂石的

Unballasted \Un*bal"last*ed\, a.
1. [Properly p. p. unballast.] Freed from ballast; having
discharged ballast.

2. [Pref. un- not + ballasted.] Not furnished with ballast;
not kept steady by ballast; unsteady; as, unballasted
vessels; unballasted wits.

Unballasted by any sufficient weight of plan. --De
Quincey.