Range taking for indirect fire while under fire in 1914

[cahoehler]

Guys

I need a simple description of how the range to a NOT visible target was taken while under hostile fire in 1914 and where accurate maps were not available.

Carl

[brett361975]

I would have thought by estimate, then to add or drop the range, someone would have had to call the fire in on the target so it must have been called on a map of some description.

ie 3 rounds at grid 12345678 fire for effect

add / drop 50 etc until the target was reached

if it was indiscriminate fire then they would fire into a grid square to destroy a target.

My thoughts anyway.

[cahoehler]

. . . . grid 12345678 . . .

brett

Thanks but I should have made clear that there was scarcity of gridded maps in the first months of the war.

The range would have to be derived from the third side of the triangle between the gun, the observation post and the target where ONLY the observer could see the gun AND the target.

Carl

[Greg]

Even where maps were inaccurate they were a starting point. Fire control tables originally used for computing fire data but still in use in my time as safety boards were set up with either a map or with a piece of gridded paper. It was possible to effectively make a map by surveying using gunfire -especially if the battery doing the firing had been surveyed in. From memory -in the RA at least- the Observation Post /Battery Commander did the fire computations coming up with a bearing and rang to target ie the information needed at the gun rather than sending information back to a command post for processing . Inaccuracies in survey etc can however be 'shot out' ie by the process of adjustment starting with approximate data-range and bearing and then by adjusting the rounds until they are in the vicinity of the target . This also takes care of meteorology/weather. This data can then be recorded in a target record book and, at least until the weather atmospheric pressures etc change can be used to reengage.

Your question asked however, how this could be done under fire so the adjustment of targets for future engagement is not the aim, so much as the engagemen of targets of opportunity. The same process would be used ie adjustment and orders transmitted by telephone or runner or even if adjusting by aeroplane by dropping a message to th battery. The latter two options were of course very slow.

Alternatively if the FOO had already fired on a target in the vicinity of the target he now identified he could make a corrrection to the gun data already supplied to the guns for that target and then adjust from there.

Greg

[bushfighter]

Carl

The target might help if it was an enemy gun, whose characteristics were known, firing towards the observer. Then the observer could use the enemy time of flight or maximum range to judge the greater part of the distance he needed.

Otherwise I think that the observer would correct his own guns using a direction line Gun to Target and adjust until he had bracketed, registered and ordered Fire For Effect.

Harry

[cahoehler]

Guys

I have never even heard or seen anything bigger than a rifle being fired BUT have stood behind a theodolite for many years (and indeed still have my own - unused these last 30 years) and know that standing in a sunny field with state of the art equipment that this is NOW a basically simple problem but fraught with a practical difficulties.

With a bit more thought about my original question, there are some basic aspects that I am missing

1. Indirect fire developed out of the needs in the Boer War (ie early 1900s) where there were in fact only sketches and very few maps.

2. Did each battery in fact have a single person range finder (eg Barr & Stroud, Goertz etc) or were some batteries still using the mekometer which required 3 men and 50m or 100m of level ground where the target was visible and THEY were not.

3. Detailed mapping would have been by plane table and alidade.

4. The observer (Battery Commander) would have to pass the solution for the triangle back to the gun and the internal angles of the triangle would then be converted into a bearing (and elevation?) for the gun.

5. The third side of the triangle would then be converted into the range after the appropriate corrections.

6. The Battery Commander would have required a graphical solution and so as not to have to use tables of logarithms and natural trigonometric functions to do the calculation on a pad balanced on his knees or on the parapet of the OP.

Carl

[truthergw]

I assume that you are talking of field artillery. At the beginning of the war, field artillery would expect to engage visible targets. If the target was invisible then the observer would give an estimate of range. Correction would take place from the observed fall of shot.

[cahoehler]

. . . field artillery. . .

Tom

This issue arose from that white stripe on the Nery gun and the existance of the sighting blades on the QF 13 pounder Mark I. See from http://1914-1918.invisionzone.com/forums/i...01605&st=91

Would indirect fire, although in use for almost a decade, then not really be applicable to field artillery fighting an offensive retreat?

Carl

[truthergw]

On the retreat, I do not think so. I think artillery fought in close support of infantry in rearguard actions. The problem more likely to be of depressing the gun sufficiently rather than indirect fire.

[bierast]

I assume that you are talking of field artillery. At the beginning of the war, field artillery would expect to engage visible targets. If the target was invisible then the observer would give an estimate of range. Correction would take place from the observed fall of shot.

German Feldartillerie regiments were originally (1914) comprised of six (six gun) batteries, three of them 77mm field gun batteries (grouped as an abteilung (battalion)) and the other three 105mm light field howitzer batteries (again grouped as an abteilung). The latter were unquestionably able to, and used to, deliver indirect fire.

During the war batteries were gradually reduced from six to four guns (which took place in the unit I am studying - Feldartillerie Regiment Nr. 48 - during 1915-16) and regiments subsequently increased to three abteilungen as standard (in winter 1916-17 in FAR 48, when the regiment were transferred to the new 241. Division) - two with field guns and one with the howitzers.

Note: heavier calibre and other less mobile pieces were the province of the Fussartillerie, a separate arm of service which of course primarily operated by indirect fire.

See this page at the Lovett Artillery Collection site for some highly informative articles on indirect fire techniques and the equipment used to achieve it.

ARL

[truthergw]

German Feldartillerie regiments were originally (1914) comprised of six (six gun) batteries, three of them 77mm field gun batteries (grouped as an abteilung (battalion)) and the other three 105mm light field howitzer batteries (again grouped as an abteilung). The latter were unquestionably able to, and used to, deliver indirect fire.

.................

ARL

Artillery were capable of indirect fire but I am dubious as to whether the British field artillery during the retreat would have found a need for it or the opportunity to use it. All accounts talk of a continuous movement with enforced rearguard actions holding off the German advance guard just long enough for the British rearguard to disengage. At the pitched battles, Mons and Le Cateau for example, I am quite sure they did employ all their skills but I suspect that most artillery engagements were of the nature of the affair at Nery.

[pjjobson]

Carl

Everything you need to know about indirect fire is to be found on Nigel Evans website "British Artillery in WW2". Don't be put off by the title there is reams of WW1 stuff on there as well, and as the saying goes, what Nigel doesn't know, ain't worth knowing. This is the link to his Pre-1914 Indirect Fire area. http://members.tripod.com/~nigelef/fc_pre1914.htm

Hope that is of some use.

Phil

[Pete1052]

I need a simple description of how the range to a NOT visible target was taken...where accurate maps were not available.

The short answer is that one would use inaccurate maps to determine the approximate range and direction between a battery and a suspected target. Even with a map that has no grid coordinates one could roughly measure the range between the battery and a target and the azimuth between the two. The sum total of the inaccuracies would most likely result in ineffective fire. My understanding is that indirect artillery fire was relatively unsophisticated in 1914 but evolved considerably during the war. I heard that the RGA was way ahead of the RHA and RFA in its indirect fire techniques early in the war.

[truthergw]

.................. I heard that the RGA was way ahead of the RHA and RFA in its indirect fire techniques early in the war.

Quite true. Field artillery expected to fire at visible targets. At most they would drop back onto a reverse slope or dodge behind some trees. Range would be fixed by guesstimate. These were mobile horsedrawn guns which fought beside and sometimes in front of the infantry.

[MikB]

Careful and conscientious compass bearings are essential, but without one of the distances that form the triangle being known accurately it's practically impossible without trail and error. The obvious candidate is the distance between gun position and observer. If there's a rangefinder with the gun, that's straightforward, but if there isn't it could still be difficult.

Regards,

MikB

[sjustice]

Quite true. Field artillery expected to fire at visible targets. At most they would drop back onto a reverse slope or dodge behind some trees. Range would be fixed by guesstimate. These were mobile horsedrawn guns which fought beside and sometimes in front of the infantry.

In October and November 1918 the RFA and RHA made a painful discovery; they could use predicted fire and their meteo adjustment was as good as the RGA, but they had forgotten how to move AND how to shoot. Their officers had also forgotten how to command battery and men in open warfare. This was recognised, but not rectified before the war came to an end.

Kind Regards,

SMJ

[cahoehler]

Guys

Thanks for the replies - I will deal with them seriatim in a series of posts.

In trying to find a reason for that white stripe on the Nery gun, I too was seduced by that darned indirect fire that is so, well sexy because you get to use those cool instruments like the big telescope, the expensive range finder, the complicated compass . . .

I missed the important issue that the on-carriage elevation of the QF 18-pounder Mark I on the Mark I carriage is only -5 degrees to +16 degrees and so its utility for indirect fire is limited.

So while we wait for the definite reason to be revealed, I am sure that the white stripe was to provide what a surveyor calls a 'target' on a green gun against a similiar background when a back bearing is taken from an observation post on a flank and thus skew to the shield. The offset of the 'target' is probably at the limit of the resolution of the contemporary optics at a distance of say 500 meters or less if the observer was very skew.

The strengthening slat was chosen because it is there and it is in a fixed relationship with the barrel and the original rocking bar sight. The white paint could have been a peace time artifact OR it was retained because it seemed like a good idea at the time. It is also likely that the white stripe did not really add to the conspicuousness of a troop of horse artillery what with all that sound, flash and smoke.

Carl

[nigelfe]

The problem with army maps of Flanders in 1914 was that their scale was not always suitable for tactical purposes. WO maps were 1:380160, 1:100,000 (Belgium) and 1:80,000 (France). However, maps weren't gridded because several years before the war the Army had decided that would make training too difficult! In fact the 'grid' on maps wasn't a grid, it was 'squaring' which is a different thing altogether, although obviously there was an underlying coordinate system, which could only be found by survey from a survey control point. Of UK wasn't alone in this, in 1914 no army had gridded maps. Chasseud's 'Artillery's Astrogers' is the best source on this subject.

For field artillery procedures for engaging targets were all detailed in the pre-war editions of Field Artillery Training (FAT), GAT for heavy and siege batteries also covers the ground. As OP-ACK has kindly pointed out my web site gives a fair amount of detail and it's taken from FAT and GAT. There were several methods and the short answer is 'it depends', no surprises there. Basically it depends on where the BC/Observing officer was in relation to the battery, but the Plotter was designed to resolve the BTO triangle. Optical range finders (coincidence type) were issued in late 1913 or early 1914. However, in November 1914 a Notes supplement was issued to FAT which stated that ranges were to be measured from the map, obviously maps of a suitable scale had started to appear (1:10,000, 1:20,000, 1:40,000 became the normal ones on the W Front).

[cahoehler]

The problem with army maps of Flanders in 1914 was that their scale was not always suitable for tactical purposes. . . .

. . . As OP-ACK has kindly pointed out my web site gives a fair amount of detail and it's taken from FAT and GAT.

. . . the Plotter was designed to resolve the BTO triangle.

. . . Optical range finders (coincidence type) were issued in late 1913 or early 1914. However, in November 1914 a Notes supplement was issued to FAT which stated that ranges were to be measured from the map . . .

Nigel

Your web site is indeed an absolute gold mine and is always my first port of call; and so the Plotter would then be used to provide a graphical solution which might not have been necessary or even possible during the fighting retreats in 1914. Seemingly the RFA / RHA battery would choose a position providing cover but providing a clear line to the target and the RHA / RFA observer would then use that old up a bit, down a bit as necessary.

Carl

[Fat Frank]

The first recorded use of indirect fire was by the Boers at Spioenkop, 24 Jan 1900 (Ken Gillings, “Spioenkop – Curtain raiser to indirect fire”, 2008), Bothma was stationed on the adjacent Koppie and directed the Boer fire VERY effectively handing victory to the out numbered and out gunned Boers. These lessons were adopted by the British Gunners almost immediately as the campaign continued.

Basically artillery fire without maps is as described in some replies above Estimate the bearing and range and adjust from there (by the way, you always adjust for line first, just logical). The use of a blank “grid” paper does allow indirect fire regardless of your position or the position of the enemy. Plot yourself (no accuracy is required), estimate the enemy, fire a shot, adjust on to the target and then adopt these corrections to subsequent opening rounds. Obviously large changes to bearing and range to the next target negate a lot of the correction but it does work.

The later use of a slide placed over the target before adjusting and marking the slide with the adjusting rounds allowed the adjusted fire to be applied to every new target with great success.

WRT to lack of elevation on the 18pndr and others, they dug out the area behind the spade to increase elevation and subsequently range. At Spioenkop they even recorded a shot of 18000 yards with 13pndr using this method (Ken Gillings,” Spioenkop – Curtain raiser to indirect fire”, 2008). Some of these dug-outs have been found in Natal recently.

I know this is not really WW1 related answer but it can be said that British Army threw away the drill book after the Boer War and many of the lesson learnt were adopted for use in WW1.

[nigelfe]

Actually as my site notes indirect fire almost certainly predates the Boers by a few centuries. However, modern indirect fire owes itself to the Russian Lt Col Guk and the German invention of the richtflache (lining plane), but all this is just the geometry. They didn't deal with correcting for non-standard conditions and some key work on this was done earlier by the Rev Blashford at Woolwich (hopefully I've remembered his name right without checking my site!).

In 1914 there were several methods and an observing officer some distance beyond the guns, ie where he might choose to use the plotter, was only one of them. It was simpler for the BC to be close to the guns (basically shouting distance) and able to see the enemy. Of course he still had to orient his guns, either with an aiming point or his director. That said, in the opening weeks of the war it would seem that too many BCs were still wedded to direct fire, despite having dial sights, etc.

Pre-1914 it was considered rather bad form to use a map (probably only a step or two up from shooting foxes!), only a few radicals used them in firing practices. The admired skill was visual range estimation.

[cahoehler]

. . . the Rev Blashford at Woolwich . . .

Nigel

What was a man of the cloth doing with this?

Ballistic Experiments from 1864 to 1880

By Francis Bashforth

Published by University Press, 1907

Reissued: Kessinger Publishing, 2008

http://www.abebooks.com/servlet/SearchResu...ments+1864+1880

Carl

[MikB]

Actually as my site notes indirect fire almost certainly predates the Boers by a few centuries.

If it did not, the 'howitzes' in John Muller's 'Treatise of Artillery' of the 1790s would have had scant purpose. As soon as artillery was capable of shooting beyond easy visual range, the forward observer had a role - which would seamlessly extend to bringing the guns onto a target in defilade.

Regards,

MikB

[nigelfe]

What was a man of the cloth doing with this?

Ballistic Experiments from 1864 to 1880

By Francis Bashforth

Published by University Press, 1907

Reissued: Kessinger Publishing, 2008

IIRC he was Professor of Mathematics at Woolwich. It was quite common for professors of all sorts of subjects to be clergymen at this time.

Headlam is his RA history volume covering the period pre-1914 states that the Burgundians used indirect fire, unfortunately he doesn't give a reference but it seems to mean 15th century or so. Not being a mediavalist I haven't a clue where the primary source material is.

I looked at the pics in Ultima Ratio Regum (the SA arty history) of the Boer period to see if any showed a lining plane sight, can't see any. I'm not sure where the French and German made guns had them mounted (or if they were even fitted to those used by the Boer). The Russians mounted them on the barrel, below is a Russian 3 inch M1900 with a 1904 lining plane, interestingly this sight is graduated as circle/600, I'm interested in knowing what the Russians actually called these units of measurements (when they multiplied them by 10 its usually translated as mil).

[nigelfe]

WRT to lack of elevation on the 18pndr and others, they dug out the area behind the spade to increase elevation and subsequently range. At Spioenkop they even recorded a shot of 18000 yards with 13pndr using this method (Ken Gillings,” Spioenkop – Curtain raiser to indirect fire”, 2008).

While digging a spade hole could be used (also in WW2 with 25 pr to get upper register fire, and of course you needed a trench for any useful arc of fire, which would be cunningly positioned so that gunners could stumble into it), getting 18000 yards from a 13 (or 18) pr is fiction (or more likely propaganda and inviting the question 'who did the survey?').

The first point being that neither 13 pr nor 18 pr were in service during the Boer War. UK used assorted 12 pr and 15 pr. The Boers used a Nordenfeldt 12 1/2 pr, some of which were taken in Brit service. This older generation of guns were not better than 13 and 18 pr!

Headlam's RA history volume for 1899-1914, appx C gives "Precis of conditions to be fulfilled by proposed new equipments, 1901", first the horse artillery gun then the field artillery gun, they are actually mostly identical except for the total wts (28 cwt with 40 rds, 38 cwt and 15 rds) and shell weights (12 1/2 lbs and not less than 18 lbs). Required ballistic performance was 6000 yards at about 16 degrees elevation with terminal velocity 600 f/s (for shrapnel), in the event both 13 and 18 pr did significantly better than this.

When 18 pr got a carriage that allowed close to 40 degrees elevation max range went up to about 11000 yds, the last few degrees of elevation to 45 always give very little increase in range. A rule of thumb is that about 22 degs elevation (ie about half max) gives about 80% of maximum range (guns have an elliptic trajectory not a parabolic one).