Jibboom

File:Boom diagram.jpg

A jibboom (also spelled jib-boom) is a spar used to extend the length of a bowsprit on sailing ships.{{sfn|Smyth|2008|p=412}} It can itself be extended further by a flying jib-boom.{{sfn|Smyth|2008|p=412}} The heel (i.e. rear and lower) end of the flying jib-boom is attached to the jib-boom, and the heel of the jib-boom to the bowsprit. The point (i.e. higher and fore end) of the flying jib-boom is generally the fore-most extent of a ship. The jib- and flying jib- booms carry the tacks of the jib and flying jib sails, respectively, and the stay for the fore topgallant mast and the royal stay.

In yachts it is a boom attached to the foot of the jib, to keep the shape of the sail in different wind angles and to allow self tacking.

Jib-boom

The jib-boom is—as the name suggests—the boom for the jib, extending its foot.{{sfn|Smyth|2008|p=412}} On smaller, merchant, sailing ships, it is commonly attached to the bowsprit by a cap and a saddle, either lashed down or secured with a crupper chain.{{sfn|Smyth|2008|p=412}}{{sfn|Nares|1868|p=45}}{{sfn|Jamieson|1829|p=530}} Alternatively, it can be attached by a boom iron and a cap, or even by two boom irons.{{sfn|Jamieson|1829|p=530}} The cap and saddle allow it to be withdrawn aft along the bowsprit as a ship enters harbour, reducing the opportunity for passing ships to glance against it and snap it off from the bowsprit.{{sfn|Jamieson|1829|p=530}}

It is octagonal in cross-section at its heel end.{{sfn|Boyd|1857|p=133}} If secured by a chain to the bowsprit, it is iron-scored at the heel.{{sfn|Boyd|1857|p=133}} At its point it is also (partly) octagonal in cross-section, the same as is the boom iron that secures the flying jib-boom to it.{{sfn|Boyd|1857|p=133}} The flying jib-boom lies against the upper starboard side of the octagon.{{sfn|Boyd|1857|p=133}}

The stay of the fore topgallant mast is attached to the jib-boom at the extremity of its point.{{sfn|Smyth|2008|p=412}}{{sfn|Boyd|1857|p=133}}{{sfn|Moore|1801}} The stay for the jib sail is attached to the shouldering at its heel.{{sfn|Boyd|1857|p=133}} Just as the bowsprit has bobstays, in order to counteract the upward force from the jib and fore topgallant stays a martingale hangs down from the point of the jib-boom to a dolphin striker, pulling downwards on the jib-boom.{{sfn|Biddlecombe|1925|p=20}}

Flying jib-boom

The flying jib-boom is secured, at its heel end, to the jib-boom by a boom iron and lashing.{{sfn|Smyth|2008|p=412}} At its point, it has a sheave for the royal stay.{{sfn|Boyd|1857|p=133}}{{sfn|Moore|1801}} Another sheave at the heel is for a heel rope.{{sfn|Boyd|1857|p=133}} It is to the point that the tack of the flying jib sail is drawn out.{{sfn|Jamieson|1829|p=530}}

References

= Cross-reference =

= Sources used =

{{cite encyclopaedia|encyclopedia=The Art of Rigging|series=Dover Maritime Series|first=George|last=Biddlecombe|edition=reprinted 1990 by Courier Dover Publications|location=Salem, Massachusetts|publisher=The Marine Research Society|isbn=978-0-486-26343-4|article=Martingale|year=1925}}
{{cite book|edition=3rd|title=A manual for naval cadets|first=John M'Neill|last=Boyd|publisher=Longman, Brown, Green, Longmans & Roberts|year=1857|url=https://archive.org/details/amanualfornaval01boydgoog|ol=23468580M|publication-place=London }}
{{cite encyclopaedia|article=Jib-Boom|encyclopedia=A dictionary of mechanical science, arts, manufactures, and miscellaneous knowledge|volume=1|first=Alexander|last=Jamieson|publisher=H. Fisher, Son & Co.|location=London|year=1829}}
{{cite encyclopaedia|article=Stay|encyclopedia=The British mariner's vocabulary: or universal dictionary of technical terms and sea phrases used in the construction, equipment, management and military operations of a ship|first=J. J.|last=Moore|location=London|publisher=Hurst|year=1801}}
{{cite book|title=Seamanship|first=George Strong|last=Nares|authorlink=George Nares|edition=4th|location=Portsmouth|publisher=James Griffin and Co.|year=1868}}
{{cite encyclopaedia|article=JIB-BOOM|encyclopedia=The Sailor's Word: A Complete Dictionary of Nautical Terms from the Napoleonic and Victorian Navies|first=William Henry|last=Smyth|editor1-first=Edward|editor1-last=Belcher|publisher=Fireship Press|year=2008|isbn=978-1-934757-41-3}}