However you may have gaps the other way; where a hull number was assigned to a ship and then the ship was canceled or destroyed before being commissioned. On a smaller scale sometimes ships get completed out of order for a variety of reasons; and since hull numbers are usually assigned when ordered you can get BC-44 completed and operations before BC-43 or BC-42 which were ordered at the same time. And then navies sometimes deliberately skip hull numbers, either individually or in bulk for various reasons.Theemile wrote:Hegemon wrote:Serious question: how about recycling ship designation of destroyed or sold ships ? For example, if the first GSN Courvosier II-class BC(P) was designated BC-44, can we conclude for example that there were 43 previous GSN BCs ever in service ?.
Hull numbers are never reused, unless you reset the entire sequence. At that point, you either renumber all your hulls (which the RMn did in antiquity with CAs), or you are so high, that starting over will cause no active or recent overlap (ie stopping at 1000, and starting again at 1 instead of 1001 when only 30 ships are in service). Otherwise, even if you built another identical ship and gave it the name of a lost ship, it would have a different hull number than it's predecessor
So even if the GSN started with BC-1 seeing a BC-44 doesn't guarantee there were 43 BCs ordered, much less built and commissioned, before it.
As a quick real world example of some of this look at the recent USN destroyers (DDG) hull numbers. DDG-114 took much longer to complete than normal in part due to trialing some new tech, so is completing about a year "out of order"; plus the USN created a discontinuous numbering block within the DDG sequence for the Zumwalt class Destroyers
The destroyer numbering sequence went (in order of commissioning)
DDG-112 USS Michael Murphy (Oct '12)
DDG-1000 USS Zumwalt (Oct '16)
DDG-113 USS John Finn (July '17)
DDG-115 USS Rafael Peralta (July '17)
And this year the USN is expected to commission DDG-114,
DDG-116, DDG-117, DDG-118, and DDG-1001
And looking back a bit further when they decided to reclassify the Ticonderoga class, while still under construction, from destroyer to cruiser the originally assigned hull numbers DDG-47 through DDG-50 were dropped, causing a 4 ship gap in the DDG hull numbering. This also caused a gap in the cruiser hull number sequence because, by coincidence, those numbers were also available in the cruiser sequence, so the changed the designation without changing the numbers. However they were only up to CGN-41 and since they kept the USS Ticonderoga's hull number at 47 (redesignating her from DDG-47 to CG-47) CG(CGN)42-46 were never assigned.
All this shows trying to count construction by looking at the latest hull numbers can be quite problematic.