They are very rare even for european standards, af far as I know if someone wants to find such tube then the best likelihood of getting it is in Germany.

You mean this one? http://www.lighting-gallery.net/gallery/displayimage.php?album=search&cat=0&pos=0&pid=47982

In Switzerland 1 Meter 25W tubes were quite common A couple decades ago. Now a few installations remains with the T8 energysaver 23W. More common is the T8 30W for shelf lighting or aquariums/ terrariums.
New 14W T8 fixtures and lamps still finds place in newly installed electric cabinets.

Used to be the American VHO format was quite common here as well for illuminating factories and hangars. The most common size was the 215W Powergroove T17PG which for example still one factory is lit by these and T12 VHOs here in the town I work.

Yes, 74cm like that Radium.

History of 1m tubes in Poland is quite specific. Nowadays they are only used in trains, specifically electric motor units EN57, EN71 and ED72 which were made in Poland for very long time. Historically there were very few examples of use outside of railways*, the only place known so far where 25W were definitely used is the building of Silesian Technical University. Those 25W tubes are still there, although they are burned and not replaced since ages. At the moment no lighting enthusiast claimed such 25W fixture though some are trying to get in contact with local electrician and do something about getting it. It is important to note that so far there is no known 220V 50Hz ballast for 25W made in Poland. Only 220V 500Hz ballast designed for lighting installation in EN57 is known. There were also 1m tubes used in tunnel in Poznań but it's unclear if those were 25W or 1m variant of 40W, there are rumors that regardless of tubes there were used ballasts for 40W. It is almost impossible to verify as that installation is long gone.


*at that time additionaly to mentioned EMUs 25W tubes were also present in EMUS and railcars imported from GDR, those EMUs and some of those railcars were already scrapped or have lighting converted to 20W and 40W

In old Osram catalog for Europe I've seen a 1047mm 38W, a little bit longer than typical 1m (precisely 970mm) 25W tubes. Where were such 38W tubes used?

中国的灯管最常见的是 T5：4 6 8 12 13 14 21 28W ，T5 12W的是特殊规格，现在几乎买不到了！
T8：18 30 36，其中10 15的也有，但是不常见
T12：20 30 40（已停产）
T5环形管：22W 32W 40W

Is there a list of arc voltages for certain tubes? I’m trying to find the arc voltage for a 5 ft F64T12 80 watt.

Recently I've seen an old polish catalogue describing local production of 17.5W 50cm T12 tubes but no one ever found such tube and there are no fixtures for such wattage therefore it may have been very small prototypical production for research purposes and was discontinued in favor of more typical 20W tubes.

One more model to add to the list: FC6T8.  (Norelco Circline fluorescent • 6 inch • 15 watt • Warm White • Manufactured in Japan.  Its etch abbreviation is FC6T8/WW.)  FC6T8 was mentioned once before, on a discussion of FC6T9 measurement.  It could be exactly right, perfectly fitting, replacement lamp for Johnson Industries Killer-Watt / KILLERWATT, the vintage incandescent to fluorescent adapter.

Some Webforum software allows wikiposts, where first post of discussion can be ammended/revised by anybody.  If Lighting-Gallery.net ever gets a wiki, then we should start a "list of fluorescent formats".

One more model to add to the list: FC6T8.  (Norelco Circline fluorescent • 6 inch • 15 watt • Warm White • Manufactured in Japan.  Its etch abbreviation is FC6T8/WW.)  FC6T8 was mentioned once before, on a discussion of FC6T9 measurement.  It could be exactly right, perfectly fitting, replacement lamp for Johnson Industries Killer-Watt / KILLERWATT, the vintage incandescent to fluorescent adapter.

Some Webforum software allows wikiposts, where first post of discussion can be ammended/revised by anybody.  If Lighting-Gallery.net ever gets a wiki, then we should start a "list of fluorescent formats".

The FC6T9 tubes were used in the "20W" Wotan/Osram circular CFLs. Trying to get hold of a spare tube, but so far no luck...

Is there a list of arc voltages for certain tubes? I’m trying to find the arc voltage for a 5 ft F64T12 80 watt.

I believe the arc drop across a F64T12 HO fluorescent tube is somewhere between 100v and 115v since a F60T12 HO tube runs at about 100v 0.8a while a F72T12 HO tube runs at about 115v 0.8a.