Ventilators

 

In his article about the Flying Cloud Duncan McLean notes that the Flying Cloud had "brass ventilators along the line of her planksheer and in her bitts".  Other McLean articles say the same thing about the Westward Ho!, Stag Hound and Flying Fish, thus it is reasonable to assume that many McKay ships were so equipped.

 

None of the Flying Cloud plans or models that I have seen include the ventilators along the planksheer or the ones in the bitts. Lankford shows gooseneck ventilators along planksheer in his instructions for building a model of the Flying Fish, another McKay clipper but does not show ventilators in the bitts.

 

Robert C. and Grisel M. Leavitt discusses side ventilators on sailing ships in their December 1994 article in the Nautical Research Journal[i].  They note that the gooseneck type of ventilators shown in The Lankford Flying Fish plans were patented by Ebeneezer Knight in 1847, but there is only evidence that they were used in two ships in the mid 1800s. Thus, it is unlikely that such gooseneck ventilators were the type used on the Flying Cloud. 

 

More likely, as discussed in Leavitt article, are that the ventilators described in the McLean Flying Cloud article, as well as in many other McLean ship descriptions were simple open top brass tubes, 2 to 2 ½" in diameter that extend upward through the planksheer up to the bottom of the main rail.  Ships of the time could have a lot of these ventilators. The Leavitt article notes that some could have as many as two between each frame.  The frames in the Flying Cloud were spaced 30" apart[ii] so that would mean that she could have had as many as one ventilator every 15 inches.  More conservative guessing would be that she had one ventilator between each pair of frames (one every 30") or one between each pair of stanchions.

 

Hold ventilation was a significant issue for clipper ships, particularly ones that spent any time in the tropics. A different Leavitt article in the same NRJ series is a good discussion of the problem.[iii]  In July 1847 Frederick Emerson patented two types of ventilators, designed to be used together to mitigate some of the problems discussed in the Leavitt article.  The ventilator in US Patent No. 5,183

 was designed to inject fresh air into a confined space and the ventilator in US Patent No. 5,182 was designed to eject stale air from a confined space.  The LeavittÕs wrote good descriptions of the use of these ventilators on sailing ships.[iv]

 

Duncan McLean in his article about the Flying Cloud reports that the Flying Cloud had Emerson's patent ventilators.  US Patent No. 5,842 is an Emerson patent that describes how Emerson thought the ventilators should be used on ships.  The list of ship fittings on pages 422 to 428 in CrothersÕ The American-Built Clipper Ship 1850-1856 lists many other ships that also were fitted with these ventilators. 

 

In spite of so many ships being listed as using Emerson ventilators, as noted in part 12 of the Leavitt series, there are no paintings or photographs showing the ventilators on sailing ships.   It is also very rare for plans of such ships to show the Emerson ventilators.  The 1986 Bluejacket plans are the only Flying Cloud set of plans I have found that show the Emerson ventilators.  Figure 19.3 on page 301 of CrothersÕ The American-Built Clipper Ship 1850-1856 shows one Emerson style ventilator being used on a half poop of an unidentified ship.  I have not found any Flying Cloud models that include the Emerson ventilators.  Thus, one must make a guess as to how the ventilators were deployed. Part 13 of the Leavitt series discusses possible arrangements based on the information the authors collected.[v]

 

Figure 29 on page 87 of George CampbellÕs China Tea Clippers includes an example of the other type of ventilators mention in the McLean Flying Cloud article – the ventilators Òin her bitts.Ó The figure is labeled Òscrew down brass ventilator tops 6Ó dia.Ó

 


[i] Robert C. and Grisel M. Leavitt, The Deck Furniture and Machinery of Large Mid-19th Century Sailing Ships - part 14: Side Ventilators, Nautical Research Journal, December 1994, Volume 39, pages 224-229

[ii] Henry Hall, Notebooks for ship-building in the United States, 1881-1883 - Volume II, Models and Measurements, 1883

[iii] Robert C. and Grisel M. Leavitt, The Deck Furniture and Machinery of Large Mid-19th Century Sailing Ships - part 10: The Ventilation Problem, September 1991, Volume 36, pages 123-130.

[iv] Robert C. and Grisel M. Leavitt, The Deck Furniture and Machinery of Large Mid-19th Century Sailing Ships - part 12 Emerson's Injecting and Ejecting Ventilators, Nautical Research Journal, September 1992, Volume 37, pages 174-180.

Robert C. and Grisel M. Leavitt, The Deck Furniture and Machinery of Large Mid-19th Century Sailing Ships - part 13: Emerson's Corresponding Ventilators, Nautical Research Journal, September 1993, Volume 38, pages 163-170.

[v] Robert C. and Grisel M. Leavitt, The Deck Furniture and Machinery of Large Mid-19th Century Sailing Ships - part 13: Emerson's Corresponding Ventilators, Nautical Research Journal, September 1993, Volume 38, pages 163-170.