Backlight Blinders
Posted: Tue Dec 31, 2013 5:18 pm
Hi,
I understand the basic principle of the backlight blinder (or back spectacle) is that they are not required when the signalman can see the front lights (unless for the information of the station staff) [Mechanical Railway Signalling Raynar Wilson p52]. My layout is LSWR 1908. I have a signal which has two arms: a starter operated by the West Box which can see the front of the signal and a Junction Up Distant which is operated by the Main Box and can see the rear of the signal. The rear of the signal cannot be seen by station staff. So, in theory, does the starter not have a backlight blinder and the distant does? Or is this confusing to the Main Box so both would have them?
A supplementary question is that there are actually two of these signals, a short (20ft) starter/distant at the end of the platform and a 45ft starter/distant repeater on the opposite side of the track. It is unlikely that the short signal can be seen by the Main Box (there's a bridge in the way among other things) but the tall signal can be seen. So, for whatever answer is given to the first question, would you not bother with blinders on the signal which cannot be seen but have them on the tall signal which can?
Regards,
Ian Spalding
I understand the basic principle of the backlight blinder (or back spectacle) is that they are not required when the signalman can see the front lights (unless for the information of the station staff) [Mechanical Railway Signalling Raynar Wilson p52]. My layout is LSWR 1908. I have a signal which has two arms: a starter operated by the West Box which can see the front of the signal and a Junction Up Distant which is operated by the Main Box and can see the rear of the signal. The rear of the signal cannot be seen by station staff. So, in theory, does the starter not have a backlight blinder and the distant does? Or is this confusing to the Main Box so both would have them?
A supplementary question is that there are actually two of these signals, a short (20ft) starter/distant at the end of the platform and a 45ft starter/distant repeater on the opposite side of the track. It is unlikely that the short signal can be seen by the Main Box (there's a bridge in the way among other things) but the tall signal can be seen. So, for whatever answer is given to the first question, would you not bother with blinders on the signal which cannot be seen but have them on the tall signal which can?
Regards,
Ian Spalding