Does anyone have any information or pictures of MH lamps that have a curved arc tube?
As well as the low wattage (below 100) MH lamps with medium bases called Halarc made by GE?
I'm also looking for fixtures, especially recessed, for the Halarc lamps.

As far as I know, curved arctubes were used just for 400W and 250W pulse start, maybe feasible for tge 175W ones but dunno if they were really made. I dont think any lower wattage ever used curved tube, it wont make much sense: To reach reasonable efficacy, the arctube and its fill (include working temperatures) must be designed to have high enough arc loading, in the 50W/cm and above. So with power levels of 100W and below, the arc would be barely 2cm long. And when such short, it can not bow that much, to need any other arctube shape than a spherical or slightly prolonged ball. Plus to reach reasonable voltage drop with such short length, it must operate at really high pressures and temperatures. So for the tube material to handle this, it can not have much complex shape, it would loose strength...

The "halarc" is a trade mark used for all metal halide lamps, not only for the curved arctube..

Here is a photo of the 400w probe start version :  https://www.lighting-gallery.net/gallery/displayimage.php?album=5215&pos=2&pid=177034

I know only the Sylvania Super Metal-arc horizontal 250-400W: http://www.lamptech.co.uk/Spec%20Sheets/D%20MHQ%20Sylvania%20MS400HOR.htm
GE Halarc:
1. http://www.lamptech.co.uk/Spec%20Sheets/D%20MHQ%20GE%20First%20Light.htm
2. http://www.lamptech.co.uk/Spec%20Sheets/D%20MHQ%20GE%20Electronic%20Halarc%20Clear.htm
3. http://www.lamptech.co.uk/Spec%20Sheets/D%20MHQ%20GE%20MXR32.htm
4. http://www.lamptech.co.uk/Spec%20Sheets/D%20MHQ%20GE%20MXR175.htm

I have a couple of Sylvania 175w MH lamps that should have a curved arctube as they were horizontal only lamps. They're coated though and I don't have the correct lampholder for them anyway. There's a couple of locating pins that require a mating mogul lampholder to assure the arctube is correctly oriented.

I have a couple of Sylvania 175w MH lamps that should have a curved arctube as they were horizontal only lamps. They're coated though and I don't have the correct lampholder for them anyway. There's a couple of locating pins that require a mating mogul lampholder to assure the arctube is correctly oriented.

By far not all "horizontal only" have curved arc tube.
But the good indication is the POM socket style: The socket has a notch guaranteeing the exactly correct position of the lamp, so the arc is really facing upwards during use. If the socket has no notch, the arctube can not be curved.

By far not all "horizontal only" have curved arc tube.
But the good indication is the POM socket style: The socket has a notch guaranteeing the exactly correct position of the lamp, so the arc is really facing upwards during use. If the socket has no notch, the arctube can not be curved.

As I already mentioned above, the base has locating pins and I checked the lamp to confirm that it does have a horizontal arctube so what you've said is a moot point.

Yeah, sorry, I was too fast typing and overlooked that...

Shortly after Sylvania introduced its curved arc tubes, GE and Venture made a similar product with POMB base but with straight arc tube optimised for horizontal use.  They offset the two main electrodes off-axis and pinched the quartz with specially profiled end chambers which gave a kind of curved effect just at the arc tube ends.  This is not so easy to see unless you find a clear lamp.  The performance was not so good as GE but was still sufficiently improved vs the regular lamps that it could justify introducing those products.  I believe Venture is still producing that style today.