query re 'arrow' references in log book of 1917

[Errol Martyn]

'Grid' Caldwell in his log book when with 74 Squadron flying SE.5a includes these entries:

'wash out. No arrow out' (6 Jun 17)

'arrow in so returned' (9 Jun 17

'chased two HA, arrow put in afterwards' (11 Jun 17)

'HA arrow. No HA (3 Jul 17

 

Can anyone explain exactly what is meant by the use of 'arrow' here?

 

TIA,

Errol

 

 

[MikeMeech]

4 hours ago, Errol Martyn said:

'Grid' Caldwell in his log book when with 74 Squadron flying SE.5a includes these entries:

'wash out. No arrow out' (6 Jun 17)

'arrow in so returned' (9 Jun 17

'chased two HA, arrow put in afterwards' (11 Jun 17)

'HA arrow. No HA (3 Jul 17

 

Can anyone explain exactly what is meant by the use of 'arrow' here?

 

TIA,

Errol

 

 

4 hours ago, Errol Martyn said:

 

Hi

 

I believe this refers to the 'Wireless Interception' system of enemy artillery machines and this is the ground signalling used by the 'Compass Stations' and connected wit the  batteries.  On 22 June 1917 a memorandum (see page 92-95 of 'The British Army and Signals Intelligence during the First World War' edited by John Ferris) has the signal consisting of 1. A white circle 17 yards in diameter.  2. A white arrow 17 yards long and 3 feet. 6 inches wide, the arrow is laid across the circle and gives direction of hostile machine.  3. A series of white strips 10 yards long and 3 feet 6 inches wide, the white strips indicate height - each strip signifying 2000 feet.

The system is also mentioned (for 1917) on page 93 of Volume 4 of 'War in the Air'.  There were earlier versions of signalling and later.  I have attached an image from a National Archive document dated 6 August 1917 below.  Fighters would be on the ground waiting these calls and would take of to intercept the pilots getting further information on where the enemy aircraft were from these signals, if fighters were already in the air then they could also see these signals.

 

 

I hope that is of use.

 

Mike

[Errol Martyn]

Many thanks Mike. That explains the system very clearly.

 

Cheers,

Errol