Semicolons and colons — ACT practice questions

At Marlow Inlet, low tide often left the fixed ferry landing more than a meter above the water. Port engineer Inez Park designed a floating dock that could slide vertically along four guide pilings. Before construction, her crew logged a complete tide cycle and marked the highest drift line on the seawall. The crew measuring¹ the channel depth at six points and compared the findings with the design drawing. They prepared three temporary guides. survey stakes, alignment cables, and painted level marks.² Together, the measurements showed where the dock could move without touching the muddy bottom.

At dawn the following week, a pile driver arrived on a work barge. By sunrise, workers had drove³ four steel pilings through the silt and into firmer material below. Each piling passed through a padded collar on the dock frame, allowing vertical motion while limiting sideways drift. During a rising-tide trial, the crew left the deck unloaded. The tide continued to rise; the platform followed without binding against the posts.⁴ A carpenter then installed the hinged gangway connecting the shore to the deck.

Park expected that the flexible gangway will remain⁵ within its safe slope as the tide changed. One concern remained, the shore-side hinge could twist if two corners rose at different rates.⁶ Workers tested that risk by shifting forty-kilogram sandbags across the deck. Load sensors recorded the weight at each corner. Because aluminum expands⁷ slightly in direct sunlight, Park repeated the measurements after the deck cooled in late afternoon. The second readings differed by less than two millimeters.

Although the first alignment looked level; a laser reading showed one corner was six millimeters high.⁸ Technicians inserted a thin spacer beneath that collar and repeated the tide trial. By the time the safety inspector arrived, all eight flotation chambers had seal⁹ by the technicians. The inspector distributed twenty-four water-filled barrels across the platform. The dock settled seven centimeters but remained above its required freeboard mark. The dock passed the load test, therefore, the crew removed the temporary braces.¹⁰ During the next ferry arrival, the platform rose with the wake and returned smoothly to level. Passengers could step aboard without the old landing's steep low-tide drop.