A little late and again from the spectacular website of Gary Martin.
Definition: Hard-up – in a bad situation.
Origin: The beams are the horizontal transverse timbers of ships. This nautical phrase came about with the allusion to the danger of imminent capsize if the beam ends were touching the water. This dates back to the 18th century and is cited in a 1773 issue of The Gentleman’s Magazine:
“The gust laid her upon her beam-ends.”
The figurative use came soon afterwards, in 1830 Captain Marryat’s The King’s Own, 1830:
“Our first-lieutenant was..on his beam-ends, with the rheumatiz.”