Military AircrewA forum for the professionals who fly the non-civilian hardware, and the backroom boys and girls without whom nothing would leave the ground. Army, Navy and Airforces of the World, all equally welcome here.
When you look at the Service life of our aircraft, the Navy
Has us beaten hands down with the active service life of some of their ships..
HMS Caroline built in 1914 and fought at the battle of Jutland, only retired in march 2011... Next to Victory that surely has to be a record, I can't imagine any of our aircraft ever reaching 97 years in Service.
When we start to build aircraft of 3-inch armour and accept a top speed of 28 knots then we'll have a fair comparison. There's also a bit of "Trigger's Broom" from Only Fools and Horses going on. How many times can you completely refit a ship and still claim it's the same one from 1914?
Been parked/berthed since 1923 so isnt that similar to a building ........ in which case lets revisit the question......? still have working a/c airworthy with military serials since 1943 , Harvard at boscombe. Not a display machine , and two meteors with MB .......
Not sure if it's one of those urban myths, but isn't the BBMF's Lancaster declared under the CFE treaty as a strategic bomber or something along those lines? Apparently something to do with those frequent non-stop round trips from Lincs - Berlin and back in one go a while back making it fall foul of some treaty wording or other.
If so, and given that it is still flying, then that would surely beat a ship that has been berthed since the 1920s?
Over 95% of the airframe, and far more than 50% of the skin. Since all the B-52s we have operating are -H models, then they are all still operating with the original model of engine (TF33/JT3D) which has been out of production since 1985.
If I remember correctly, most ships last about 20 or 30 years.
That's about right, but as usual, it "depends". A ship's hull has a fatigue life, the difference being that repair is often straightforward; any old dockie with a welding torch can weld up the cracks (seen it done, just an hour or so before sailing in a Type22 Frigate). If the cracking is too extensive it's merely an economic decision to write off the ship, not an engineering decision.
RN vessels like the Type42 destroyer were built light for speed and performance. The thin steel hulls would quite often rust through a fuel tank, venting it to the sea. The solution? Fill the tank with concrete and carry on until next dry docking! Planting one on top of a rock near Australia can be a good thing - whilst you're repairing the tears in the hull you might as well sort out the other structural issues whilst you're at it.
The Type23 frigates were designed for an anti-sub role. Such a role calls for trolling round the oceans at slow speed listening for a prowling submarine, i.e. easy conditions for the hull. However they actually spent their time darting hither and thither at high speed doing anti-drug patrols, Gulf deployments, etc, and wore out their hulls much quicker than planned.
The newer ships, e.g. the Type45 destroyer, are made to commercial build standards; much thicker steel and should last a lot longer. Maybe the aero world should use half inch steel; jets that really last . Better engines (RR Trent derived gas turbines with recuperation these days) make up for the weight to a good extent. They've also learned the lesson about building a class of ship at a decent size from the very beginning. Allows for much cheaper mid life updates, so the overall lifetime cost is lower. And a longer ship is more hydrodynamic so the drag is better too.
As a point of order, while Ocean's hull structure and systems may have been built to "commercial" standards - specifically Lloyds Rules & Regulations for the Classification of Ships - T45 and QEC are not. They are built to Lloyds Rules & Regulations for the Classification of Naval Ships, which were developed by incorporating much of the military load and military structural design practices previously contained in Naval Engineering standards etc.
Because these rules use broader brush loads (ie you tend to derive a worst-case load and apply it more extensively) than the multiple iterations and piece-part load modelling previously used in NES practice, this tends to lead to simpler "heavier" structures and thicker plating, which is no bad thing. At a rough estimate using Lloyds Rules as opposed to the old NES/SSCP23 design practices puts about 5-10% on the structural weight of a ship.
That said, much of the cracking issues evident in older ships (eg T42) was directly attributable to to p1ss-poor detail design. Bulkheads not landing on bulkheads is just asking for fatigue cracking. T23's are having issues because in some cases the MoD bulk-bought steel plate without the correct rolling margin, leading to in effect thinner than designed plating, not helped by the ships being significantly heavier than they were designed to be. However, replating is always do-able, just pricy.
MSB - you ought to be careful with the Great White Turbine (WR21) aboard the T45. It has a recuperator and an intercooler and is very complex. Trouble is there are only 12 of them (unlikely to be more) and I'm led to believe that elements of their "complex bits" are supplied by Messrs Bubba and Cletus of Bumf8ck Ak, who may not be in business throughout the life of the ships.......
Those nice people at GE who offered the successful and very popular LM2500 instead were of course turned away by BuffHoon (remember him??!)
Location: uk mostly, desert lots, searching for lost posts
One was once told - at a Cockers P on HMS Caroline - that she would have enormous scrap value as she was/is one of the largest potential sources of "pre nuclear" steel.
Apparently all steel manufactured since 1945 has accrued some elements of radioctivity - "pre-nuclear" does not so it is an essential and rare (read expensive) part of some nuclear-type measuring instruments.
Sounds plausible to me, but may just be the nuclear age version of the "golden rivet", foisted upon a gullible crab at a Cockers P........
I don't own this space under my name. I should have leased it while I still could
Join Date: Dec 2002
The German Grand Fleet at Scapa Flow is the usual source quoted for uncontaminated steel.
This low-background steel is used in the manufacture of radiation-sensitive devices, such as Geiger counters, as it is not contaminated with radioisotopes, having been produced prior to any chance of nuclear contamination
This suggests that there is no large market for such uncontaminated steel.