To distinguish between yards, gaffs and booms, remember the following:
• Yards – normally horizontal, attached by their centre at some height up a mast. They may be at right angles to the fore and aft line, or pulled round hard to either side. In harbour they were sometimes cocked-up to allow ships to berth alongside one another without tangling yards, since they usually projected beyond the ship’s side.
(x)
They are also seen sent down (lowered from their normal place onto the deck) again usually in harbour and they could be over 30m long. Studding-sail, or stunsail booms, were extensions to the yards to allow extra areas of sail to be set in light weather. They were stowed underneath the yard and run out when needed.
• Booms – again mostly horizontal, and usually with one end attached to a mast on a swivel, and the other attached to a corner of a sail, whose foot may also be laced or otherwise secured along the boom.
(x)
• Gaffs – one end attached to the after side of a mast by a swivel, the other to the top corner of a sail. They were normally tilted up at an angle of around 40°, but the angle could be varied, and the gaff could also be lowered until it lay on top of the corresponding boom, if any.
All spars have gone through the same sequence of materials as masts
Why was there a crane parked right in front of Arena Zagreb, it's still beyond me - this photo was taken a few years after the Arena venue was built and opened. Nonetheless, there it was, doing… something. June 2011.
Taken with Pentax K20D digital camera and Sigma AF 10–20mm F4–5.6 DC EX HSM ultra-wide-angle lens.