Tank Tactics at Cambrai
Work in progress
Prior to Cambrai, on 30th October 1917, the Tank Brigades were issued with a copy of "Tank and Infantry Operations without Methodical Artillery Preparation" (OH p349ff)
This document was designed as a guide and was supposed to be modified to allow for differing tactical conditions.
The document includes several diagrams, one of which shows a company of tanks leading an infantry battalion; this is the only diagram which shows such a formation and is the only one reproduced in the Official History. The infantry battalion is deployed with two companies in advance and two in support, each company is deployed with two platoons in advance and two in support, and each platoon is deployed with two sections in advance with two sections in support, each advancing in column following the tanks. Each platoon is led by one tank, eight across the front of the whole battalion, these tanks are designated as main body tanks. 100 yds in advance of the main body tanks are deployed four advanced guard tanks, one for each pair of main body tanks, thus each section of three tanks forms a triangular wedge. The diagram doesn't indicate how far behind the tanks the leading infantry sections were to be, the document simply states the infantry were to follow immediately behind the tank (para 14), and ensure they stayed at least 25 to 30 paces behind the tank when it was crossing wire to ensure they did not get tangled in any strands (para 18).
On 20th November each on the five infantry divisions attacked the first objective (Blue Line) with two brigades alongside one another in advance and the second objective (Brown line) with the remaining brigade. Each Brigade was supported by two tank companies. i.e. one per attacking battalion, (One of 62nd Division's Brigades was only supported by a single company, 19 from "G" Battalion, but this had been reinforced to a strength of 30 tanks); survivors from the first wave of tanks were also to support the attack on the second objective.
Only "C" and "F" Battalions, operating with 12th Infantry Division, on the far right flank appear to have adopted the tactical scheme relatively unaltered. Both battalions deploying 24 tanks in front of the first wave of infantry, the distance the infantry were to follow behind the tanks is not given.
"A" and "I" Battalions, operating with 20th Division, and "H" and "B" Battalions operating with 6th Division, each deployed eighteen tanks in front of the leading infantry wave and six behind the wave in support. The supporting six tanks were to start 20 minutes after the leading wave of tanks; i.e at D+10 as opposed to D-10. The majority of the leading sections attacked in wedge; but where tactics and terrain dictated it some did advance in column (i.e. "B" battalions flank sections).
The infantry were to follow 75 yards behind the main body tanks according to "A" Battalion's war diary (W1) or 70 yds according to Capt. Hickey ( though he did advance with the second wave). (S61.p101).
20th Division's attack was complicated by the presence of the fortified village of La Vacquerie.
The first wave (five infantry companies, three from 7 SLI and two from 7 DCLI) was to capture La Vacquerie and the trenches to the NW of the village.
The 7 SLI fourth company was in reserve. Each 7 SLI assault company followed one section of three tanks, the infantry advanced in artillery formation. (S93.p190f) The two 7 DCLI companies followed three sections of tanks. (7 DCLI war diary)
The second wave was to capture the Hindenburg line (Blue Line), this consisted on two companies of the DCLI, supported by six tanks, and two companies of the 12th Kings also supported by six tanks. (7 DCLI War Diary)
The third wave was to capture the Brown line. The remaining two companies of the 12th Kings and all four companies of the 7 KOYLI were to advance supported by six tanks plus any of the surviving first wave tanks. (7 DCLI War Diary)
III Corps infantry were "trained to advance by rushes in open order behind the tanks and to avoid closing on the tanks" (WIIICorps.p3)
Infantry were to assist the tanks when necessary by improving the gaps the tanks made in the wire and by providing covering fire and by providing causeways with their shovels (WIIICorps.p6 and 7)
"D"and "E" Battalions also deployed eighteen tanks immediately in front of each brigade. However the other six tanks were not deployed as a reserve but were instead deployed 100 to 200 yds in front of the main body tanks and were ordered to crush the sire and subdue the MGs in front of the enemy's main line; it is worth noting that this is much the same mission as given to the advanced guard tanks. An diagram attached to the 1st tank Brigades report on operations indicates there were no advanced guard tanks, each section of three tanks were deployed in line abreast, not the wedge formation used elsewhere; the infantry in the leading sections were to follow in line 150 - 200 yds behind the tanks; one platoon of infantry following each three tank section.
Both infantry assault battalions (1/8 Argyll and 1/5 Seaforth) following "E" Battalion's tanks advanced two section's directly behind the wire crushers to help clear the outpost line; the fighting tanks were followed by three platoons advancing abreast to capture the Hindenburg front line, three platoons then passed through and captured the Hindenburg support line (Blue Line); two platoons passed through to capture the grand ravine and finally four fresh platoons to capture the railway embankment. support line. One company of infantry was held in reserve. The infantry advanced in short section rushes. (Infantry battalion's war diaries) . This agrees with the illustration in the Summary of Operations which shows eight tanks (6 fighting and 2 wire crushers) leading a single company with two infantry platoons alongside one another and two following in support (W21) . The other sources which state that each infantry company was supported by 12 tanks (3 wire crushers and 9 fighting tanks) (W5o) are therefore incorrect.
It is worth noting that the the 1/5th Seaforths (51st Division) supposedly did not commit six of its platoons (from the lead companies) to the attack on the 20th November as they had been clearing paths for the tanks on the 19th (S92. p127). However the plan in the war diaries indicates twelve of the sixteen platoons were to attack.
"G" Battalion was the only battalion operating with the 62nd Division and was thus reinforced to sixty tanks, thirty of which operated with each infantry brigade. A diagram attached to the "1st tank Brigades report on operations" indicates "G" Battalion used the tactical formation recommended in "Tank and Infantry Operations without Methodical Artillery Preparation", albeit modified by re-designating the advanced tanks as wire crushers and having the infantry following 100 yds behind the main body tanks. However the "1st Brigade Tank Corps Summary of Operations 20th to 23rd November" indicates there were six wire crushers in advance of each brigade and eighteen tanks with the first wave. Both appear to be correct as they apply to 19 and 21 companies as follows:
As indicated in the narratives 19 company (24 tanks) on the left was supposed to lead two battalions of 185 brigade forward using the formation laid out in the diagram; albeit after some of the tanks had dealt with features in the outpost line and returned to the formation. 21 Company on the right (16 tanks) was probably deployed in the same manner as "D" and "E" Battalions (four wire crushers followed by twelve tanks in line), however the tanks had to swing right to avoid the cut down trees in Havrincourt Wood / Femy scrub and then swing left to regain the front of the infantry; the infantry platoons were instructed not to follow individual tank sections of 21 Company, probably due to their right - left movement .
The diagram for 62nd Divisions attached to the "1st tank Brigades report on operations" shows the infantry attacking four platoons abreast but also also indicates each infantry company is missing three sections, twelve sections in total, or three platoons worth.
Regardless of the formations actually adopted they worked everywhere, the Blue line was captured rapidly and with relatively minimal losses to the tanks and infantry.
The attack on the Brown line was successful everywhere except at Flequieres village on 51st Divisions front. Fuller states this was the fault of the Division for adopting a different tactical formation and having the infantry too far behind the tanks to support them when they were engaged by German batteries firing over open sights. (S72.p149)
Various modern historians have questioned Fuller's conclusion, pointing out that other factors caused the destruction of the tanks and thus the failure of the attack at Flesqueires.
Firstly the terrain favoured the defender, the second line was on the immediate reverse slope of a ridge-line, as the tanks crossed the ridge they were knocked out one by one on the skyline.
Secondly the German batteries positioned behind Flesquires had been specially trained in Anti tank tactics.
Lastly the batteries in this area had not silenced by counter battery fire and attempts by ground support aircraft to silence them were hampered by the weather.
In addition some historians have argued that other divisions (most notably the 62nd) adopted a similar scheme to the 51st and their attacks progressed well. It is worth noting that Fuller's main complaint, that the infantry were too far behind the tanks, may have been true, however the infantry were apparently positioned a similar distance behind the tanks in other divisions and those division's attacks succeeded.
Sources
WIIICorps = III Corps War Diary, G.S.1/1. Dated 10.11.17, Instructions No 1, pdf download from PRO Kew, WO-95-677-2
W4a = D Battalion War Diary PRO WO 95/110
W5o - "E" Battalion Tank Corps Operational Order No.7 in PO WO 95 / 111
W5r - "E" Battalion Tank Corps Report on Operations 20th November 1917 (dated 26/11/1917). PRO WO 95 / 111
W8o - "H" Battalion Tank Corps order No 1. and appendix "B"B to this order in PRO WO 95 / 114
W21 - 1st Brigade Tank Corps Summary of Operations 20th to 23rd November in the 1st Tank Brigade War Diary. (Signed 9 December 1917). PRO WO 95 / 98
W21bg - Battle-graphs attached to above Brigade report of Operations PRO WO 95 / 98
WMH - Henshall papers, IWM 73/126/1
"16th Infantry Brigade Operational Order No 232. 14th Nov 1917".
S78 - Tank Action in the Great War (2009) Ian Verrinder