Meteorology At The Battle Of Loos

[knocker]

After the British Expeditionary Force went to France in 1914, daily forecasts were provided for its guidance from the Meteorological Office, then under the direction of Dr. W. N. Shaw, with its headquarters in Exhibition Road, South Kensington. When the first Zeppelin raid was made and dropped bombs in the Eastern Counties, it was suggested that the objective had been London and that the design had been frustrated by an unforeseen upper wind that was immediately verified by the meteorological reports. This information stimulated the military authorities, and as it was shortly followed by the first German gas attack in the spring of 1915 it was recognized that the Army in the Field (which then included the Royal Flying Corps) required a meteorological service in its operational area. This was begun in a very small way in June, 19I5, at G.H.Q. St. Omer with two Officers and a Corporal-the former from the Meteorological Office and the University of Aberdeen, the latter from the Gordon Highlanders, then in the front line pear Ypres. The service grew and was established as the Meteorological Section of the Royal Engineers after the battle of Loos, prior to and during which meteorologists had proved to the satisfaction of the Army Command that the forecasts and information which they furnished were trustworthy and essential to the success of operations.

There is a caveat to this. To compile as good a forecast as he could given the paucity of information it would seem common sense that the forecaster be given all the details of the forthcoming operation. This was not the case. On one occasion-this is difficult to believe- a Meteorological Officer was asked for a weather forecast and when he asked for the time and place received the answer, “I can’t tell you that-it’s too secret-give me your ordinary weather forecastâ€.

To provide some context prior to Loos a brief description from Haber of the German gas attack at Ypres. It was just after 1700 on Thursday, 22^nd April 1915.

The simultaneous opening of almost 6,000 cylinders which released 150 t of chlorine along 7000m within about ten minutes was spectacular. The front lines were often very close, at one point only 50 m apart.The cloud advanced slowly, moving at about 0.5 mlsec (just over 1 mph). It was white at first, owing to the condensation of the moisture in the surrounding air and, as the volume increased, it turned yellow-green. The chlorine rose quickly to a height of 10-30 m because of the ground temperature, and while diffusion weakened the effectiveness by thinning out the gas it enhanced the physical and psychological shock. Within minutes the Franco-Algerian soldiers in the front and support lines were engulfed and choking. Those who were not suffocating from spasms broke and ran, but the gas followed. The front collapsed.

The British took less than three months to prepare for retaliation but events didn’t turn out as expected.

In Haig's view the only redeeming feature of the Loos battle plan, and one in which he was to grow ever more confident, was the recent availability of asphyxiating gas. Having seen the rent torn in the Allied lines at Ypres on 22 April by the first German gas attack, he envisaged the new weapon compensating for the lack of artillery. It was agreed that there was reason for a degree of optimism -but only if the attack was a surprise, the wind favourable, and sufficient gas cylinders brought forward. In preparation, therefore, 8,000 men transported 5,500 cylinders of chlorine gas into the front lines. It was almost exactly half the number requested, so 11,000 smoke candles, 25,000 phosphorus grenades, and 10,000 Stokes mortar smoke bombs were supplemented to at least create the appearance, if not the toxic effect, of the real thing.

Sappers of the newly formed Royal Engineer 'Special Companies' under the command of Major C. H. Foulkes RE (the initiator of panoramic military photography during the Boer War), tucked the unwieldy cylinders into specially made recesses beneath British parapets, running out hoses into no man's land just as the Germans had done at Ypres in April. Their field company colleagues installed 3,500 trench ladders and prepared 2,500 footbridges for crossing German lines. Then everyone prayed for a westerly breeze for Zero Day.

The following are notes made by Captain Gold the senior meteorologist to the 1^st Army that illustrate vividly the advice given and the action taken.

“I had for some time been sending Col.Charteris (Intelligence 1^st Army) telegrams…. To say the wind would be between S.W. and N.W. and between 4 and 12 miles per hour at dawn the following day. ‘America’ meant ‘yes,’ ‘India’ meant ‘no,’ ‘very good’ meant ‘practically certain,’ ‘good’ meant ‘fair confidence’ and ‘indifferent’ meant ‘not much confidence’.

“I left G.H.Q. at 12 noon (on the 24^th September, 1915)….after my arrival at Advance H.Q. 1^st Army General Butler took me to see Sir Douglas Haig-who congratulated on the success of my forecasts-’15 right and a1/2 wrong’ he said. With him were Sir Henry Rawlinson and General Gough. I showed them the charts (of conditions at 7a.m. on the 24^th of September) and explained to them that conditions were not very favourable but they were not unfavourable, conditions were in a state of flux and it was not possible to forecast with anything like the same certainty as during the preceding period of stable conditions. Sir Henry Rawlinson wished to know if the Scandinavian anticyclone was likely to reassert itself and bring a fresh period of easterly winds. I said it was improbable for some time and if the wind went round to the East it would only be temporary.

"My deduction (from the 6 p.m. chart}-was 'much more favourable' and I gave this as my opinion. Upon it, General Butler informed me they had decided to go the whole hog but I was to go round again at 2 a.m. . . .

“The 1 a.m. message was received at 2.35 a.m. and rapidly charted. . . . I went quickly round to the Chateau and was met by General Butler who took me immediately upstairs to Sir Douglas Haig's room. Sir Douglas said 'well let us see your' chart. ~what are the indications?' I placed the chart before him and told him that conditions were still favourable but only just so. He asked me what I advised as to the time for the attack. I said if it were not for the risk of change in the general situation it would be better to wait until 9 a.m.or later, as the ordinary diurnal effect would tend to take the wind further round to west and, to increase its force ... having regard to this risk (of change in the general situation) I thought no opportunity ought to be let slip. He immediately told General Butler to give instruction for it to be at 5.40 a.m. and to inform Gough and G.H.Q.

"It was a drizzling rain and dawn was just beginning to break-there seemed to be practically no wind. Sir Douglas asked: Would it be better later if they postponed it? I nervously said there would probably be more wind after the rain ceased. General Butler and Col. Davidson went into the Chateau, picked up telephones and said, , How long would it take you to get orders round for the attack to be postponed; reply to General Butler came ‘It couldn't be done,' whereupon he asked for Gough and told an A.D.C. to come to the telephone. We went out again and General Butler said that at present they were all 'standing by.' Sir Douglas asked for the Gas Adviser. General Butler called an orderly but he did not seem very certain where the Gas Adviser was so I said' I'll go, Sir, it will be quicker, and ran for Foulkes. We ran back and Sir Douglas said ‘I suppose they themselves will not let it off if the wind is not favourable.'Foulkes said' that is so, Sir.' I said the general drift would be towards the east although in some places there might be temporary back currents: Somebody produced a cigarette and lit it; the smoke drifted slowly off to the East. (A General commented on the usefulness of the cigarette: one could fire a mine with it: get the direction of the wind and so on.) The Gas Adviser said the velocity was alright, only the direction was the doubtful matter. Sir Douglas said' Let it go foreward' and walked off to the Observation Tower: while we all stood and watched the drifting smoke from a factory chimney which had just begun to pour forth. There was no mistake about it being from the south-west, but it was rather slow.... The

scene in the dull grey morning had been a memorable one: the red brick Chateau; the trees with hardly a leaf stirring, the soft rain, the three Generals, one or two Colonels, a Major, the Gas Adviser and the Meteorologist. . . . I felt extremely pleased when I saw a report that an observer had seen the clouds of gas rolling towards the enemy's lines, though the Gas Adviser remarked that first reports were near always optimistic,"

The wind measured and, reported by trained meteorological observer from 8 places in the forward area behind the front at 5, 6 and 7 a.m. were all between south and west-at 6 a.m. one was south, one W.S.W. and the other S.S.W. or S.W. by W. except one, which having been S.W. by W. at 5 a.m had fallen calm by 6 a.m.

In the event the gas attack proved pretty disastrous. A description by Robert Graves gives the flavour.

“It seems that at half past four an R.E. captain commanding the gas company in the front line phoned through to divisional headquarters: 'Dead calm. Impossible discharge accessory.' The answer he got was: 'Accessory to be discharged at all costs.' Thomas had not overestimated the gas-company's efficiency. 'The spanners for unscrewing the cocks of the cylinders proved, with two or three exceptions, to be misfits. 'The gas-men rushed about shouting for the loan of an adjustable spanner. They managed to discharge one or two cylinders; the gas went whistling out, formed a thick cloud a few yards off in No Man's Land, and then gradually spread back into our trenches. The Germans, who had been expecting gas, immediately put on their gas-helmets: semi-rigid ones, better than ours. Bundles of oily cotton waste were strewn along the German parapet and set alight as a barrier to the gas. Then their batteries opened on our lines. The confusion in the front trench must have been horrible; direct hits broke several of the gas-cylinders, the trench filled with gas, the gas-company stampededâ€.

The total British gas casualties between 25 and 27 September were 2,632, of whom seven died. The 2nd Division astride the Canal and the 15th Division just opposite Loos suffered most, 1,052 and 464 respectively The gas casualty rate was 4.4 per cent of all killed and wounded at Loos, a relatively high proportion by comparison with later gas attacks.

I don’t think any blame can be put on the forecast. At best the weather was borderline for a gas attack (not to forget in some areas it was quite successful) with not enough of a westerly component to the wind or indeed enough strength. Plus you had the length of the front which meant variations in conditions, that although maybe slight, made a vital difference.

One thing remains a puzzle. In another memoir Captain Gold comments on the brilliant use, by Capt. Bisham and Capt. Lamb, of katabatic winds, which provoked the enemy’s comment that the British used gas when the meteorological conditions didn’t justify it. This comment is obviously correct given the source but given the battlefield at Loos was extremely flat I’m puzzled as to how this was achieved. Any suggestions gratefully received.

References.

Weather in War, Army Journal, October 1943. Courtesy National Army Museum.

The Meteorological Office and the First World War, Met. Mag, 1943.

The Poisonous Cloud, L.F. Haber.Clarendon Press, Oxford.

Goodbye to All That, Robert Graves, Penguin Classics.

Map of the Battlefield, courtesy The Battlefields of The First World War, Peter Barton

Infrantry advancing through the gas

Map of battlefield

Loos today

Edited October 25, 2010 by weather ship

[johnholmes]

fascinating post there Fred-thanks

you have a long way to go to catch up with Coast and his superb cover of the Battle of Britain mind you!

[knocker]

fascinating post there Fred-thanks

you have a long way to go to catch up with Coast and his superb cover of the Battle of Britain mind you!

Wouldn't even attempt it John. Any thoughts on this katabatic wind business? It's just about dead flat around Loos but I suppose a small ridge would suffice.

[johnholmes]

Wouldn't even attempt it John. Any thoughts on this katabatic wind business? It's just about dead flat around Loos but I suppose a small ridge would suffice.

I'll have a closer read and see if I come up with anything?