What about the manpower issues? Zabecki seems to ignore entirely that the Germans, British and French were running out of men? By March 1919 where was the new levees to come? The Americans?
I forgot to answer this when it was posted McP. Sorry about that. For the Allies, yes, they were counting on American manpower. Technically the British did have some manpower they could tap as they maintained a very large and probably unnecessary Home Army right through the war. The British also had grade requirements for recruits that were, by French and German standards, overly selective. They had relaxed standards somewhat over the winter of 1917 but they were still more restrictive than either the Germans or French, AIUI.
Therefore,
technically, the British could probably refill their losses to a greater extent than they did IOTL. However, the reluctance to relax standards and release men from the Home Army seems to have not originated from the political level but from the General Staff. Therefore it seems unlikely that they would undertake such measures unless they were much more desperate than OTL.
So, yeah, they were waiting for American manpower. The Germans, AFAICT, had basically no manpower reserves remaining. Win or lose, what men they lost were probably not going to be replaced.
OTOH Alexander Watson’s Ring of Steel is available for US$20.99 from Amazon.com and GB£12.99 from Amazon.co.uk
Still a paywall, but a more affordable one. For myself, with my families current situation, I am free to spend time on this alternate history hobby, but at present can give it little money. Therefore what I have is what I can beg, borrow or find free on the internet and unfortunately Watsons work is not among that group.
That said, I have heard good things about Watsons work, and it remains on my Christmas list. I have read some reviews of his work, and listened to an online lecture from him on the Seige of Przemysl, which is another area of research for him.
This is pretty much the same ground covered by Zabecki
It is, and it is not unique to them either. I suspect due to the similar numbers that Zabecki and Watson are using in regards to train capacity, that they are both using A.M Henniker's "Transportation on the Western Front 1914-1918" for that part. It is a part of the British Official History as compiled by James Edmonds. I have seen the same information elsewhere as well.
In regards to this portion:
. The British would indeed make disastrous tactical errors in the Spring of 1918 and their command structure, hard-wired for static warfare, did break down in the rapidly changing environment produced by mobile war. However, the Germans underestimated the rank and file’s toughness, which did much to compensate for the failure of leadership and tactical skill.
I would counter with
"The Operational Role of British Corps Command on the Western Front, 1914-18 by Andrew Simpson".
Pg.174-175
Maxse has been accused in a number of quarters of prematurely withdrawing XVIII Corps behind the line of the Somme on the 22nd, leading to the opening of a gap between his corps and Watts' XIX Corps, and between them and VII Corps. His biographer dismisses the wildest of the allegations, such as Edmonds' gossip to Liddell Hart that Maxse had been absent from his HQ for 48 hours after a shell burst nearby. 7 ' Maxse himself said in a letter to Edmonds that he objected to being made a scapegoat and claimed that he had planned his withdrawals carefully. 72 And an examination of the expanding frontage of XVIII Corps (from 16,000 yards on 21st to 22,000 on 22nd March) makes it seem possible that the opening of gaps was due to lack of troops as much as carelessness on Maxse's part. In any case, the role of corps commanders from now on was to retreat as ordered and to feed into the line whatever reserves they were given.
Travers makes much of the collapse of command in Fifth and Third Armies as they withdrew, but this is harder to prove than it seems. Although he produces a number of anecdotes from which he generalizes that corps and divisional staffs lost touch altogether and sat in their HQs, other sources contradict this. A note in the VII Corps files, which apparently was the result of the GSO2(I) bringing news from 9th Division, gave news of the situation on the Green Line in the late morning of 23rd March. 73 The commander of V Corps, Lt.-Gen. E.A. Fanshawe, wrote that because "it was difficult to grasp the situation, unless one went to see," his BOGS went up to the front on 24th March and Fanshawe himself on the 25th (as far as he was concerned, these were the worst two days for his corps), and they 'motored' round his divisions on 26th March. 74 This is not to say that communication problems did not arise; they were bound to, under the circumstances. Lt.-Gen. J.A.L. Haldane, GOC VI Corps, noted in his diary that Maj.-Gen. Feilding, the GOC of the Guards Division, complained of being out of touch with corps for six hours on 26th March, but on checking, Haldane discovered that telephone messages were exchanged between his and the division's HQ five times during these six hours, and a liaison officer had been sent by corps to division. He felt that Feilding nevertheless expected too much of the limited communications available in open warfare.75
However, what the last two paragraphs demonstrate once again is the difficulty in establishing precisely what went on; anecdotal evidence, though attractive, is no more clear-cut than more official documents, and in the case of the latter it may be easier to see what axe the author had to grind.
Pg. 178-179
It can be seen from the foregoing that the problems of the BEF in March and April 1918 stemmed from lack of manpower, and, especially in March, were exacerbated by severe casualties and the elongation of the front as it fell back. Given the limitations of the sources, it is difficult to establish precisely what occurred at times; accounts even in reputable works are contradictory. However it is apparent that command and control did not collapse, notwithstanding severe problems at times. Nevertheless, the loss of initiative at the start of each attack was difficult to recover from, given the lack of reserves on these fronts. Had the manpower been available, perhaps the BEF would have been better advised to attempt its defence on the model used in front of Arras, rather than in a pale imitation of the German system. In fact, the German attack in March was notable for its initial high tempo - much higher than the BEF's - which was another reason for the loss of initiative. As well as having stronger forces, the Germans were acting faster, and once the defenders were off-balance it was easier, given the problems which led them to retreat from their defences, for the Germans to keep them in that state. However, fatigue and logistic incompetence led to the slowing down of the attack - a reduction in its tempo - and the restoration of equal tempo by the time the Michael offensive ended. 91 In April the disparity in tempo was far less, and the advance consequently smaller.
In spite of its severe losses and the difficulty of stemming the tide of German advance, particularly once the loss of their front lines reduced their manpower while also extending their front, Fifth Army and its subordinate formations remained functioning entities.
The real vulnerability of the British Expeditionary force was logistical. All armies on the western front required extensive railway systems to keep them supplied, but the network behind British lines was barely adequate. It possessed two choke points, the forward marshalling and switching yards in the French towns of Hazebrouck and Amiens. Through each passed around half of the supplies dispatched from Britain. Hazebrouck, situated 30 kilometres behind the line in the north, channelled materials that came through the ports of Boulogne, Dunkirk and Calais. Amiens, 60 kilometres behind the British southern sector’s front, helped distribute goods from Rouen, Le Havre and Dieppe, and also handled 80 per cent of north-south traffic along the line. Any German advance would have had to be deep but the reward for capturing these key rail nodes would have been immense.
I have no disagreement with this portion. As I have said, Amiens and Hazebrouk are the best targets available to the Germans for the Spring Offensive. However, I am not convinced that they would be able to get there.
Zabecki says this (page 195, in his analysis in Chapter V, in case anyone wants to check the context):
The generally accepted explanation for Haig's decision to keep the Fifth Army weak is the assumption that Gough had the depth to fall back into, and there was nothing critical in his rear--except Amiens, which was at a greater depth than most World War I commanders would have believed to be vulnerable. And, based on a 7 March agreement between Haig and Petain, the French were to put a reserve of six divisions immediately behind Gough on Haig's request. Travers, however, argues convincingly that this is a post facto rationalization to cover the fact that Haig and GHQ were slow to recognize the threat at the southern end of their line, and that for several days into the battle they believed the main danger was on the northern end of the MICHAEL attack. The irony here is that certainly was the original German intent. The "open space" explanation also ignores the critical danger of a Franco-British rupture.
My concerns with Travers objectivity have, I think, been made already. I believe Travers, and through him Zabecki, is too quick to dismiss the accepted wisdom as to the deployment of the BEF. Even if he is right, and Haig did not intend it this way, it is a valid point. The following Map will help to illustrate:
In order to successfully take Amiens the Germans have to get there before significant reinforcements can arrive from either the French to the Southeast or the British to the North to block them in front of Amiens. The obvious lines of defense in this area are the Ancre to the North of the Somme and the Avre to the south of it. With these two rivers held in any strength it would take a major effort for the Germans to dislodge the Allies and move on to Amiens itself. Therefore, the Germans need to move fast enough to be in Amiens before the British and French can significantly reinforce these areas. IOTL the French had First Army in front of Amiens and Third Army Backstopping British Fifth Army by the 26th. Meanwhile, British Third Army was already establishing itself on the Ancre. So the Germans have 4-5 days to make it to Amiens.
The Germans used three armies IOTL, Seventeenth. Second and Eighteenth. Of the three, Seventeeth is actually centred facing the highlands around Arras. This is very good terrain for defence, and the British are well entrenched. OTL assaults here made little headway and were quickly abandoned. Thus Seventeenth Army is unlikely to do any more than be a supporting formation and flank guard to the Second Army in Michael and Sixth Army (to the north) in Georg. Second Army is between the Arras highlands and the Omigon River. Eighteenth Army is to the south of the Omigon, including St. Quentin and as far a La Fere with the southern portion of it following the Oise.
The commonly quoted distance from the German front line to Amiens is 60 km. However, this only applies from the closest part of the German line. St. Quentin was the closest point south of the Somme, at 71 km. Most of Eighteenth Army's line would have been 80 km or more from Amiens. Conversely, Eighteenth Army is facing the British Fifth Army sector, which is by far the weakest part of the British line. Fifth Army has the least density of all the British Armies (average of 3.23 miles per divisional front), is made up overwhelmingly of second line Territorial and New Army Units and is taking over a section of the Front from the French that was in poor condition. It is also on poor defensive terrain and the need to maintain contact with the French meant it could not retreat directly on to its lines of supply. Third Army, meanwhile, has the second densest line (2 miles per divisional front), is made up overwhelmingly of veteran frontline divisions and can anchor itself on its left in the highlands around Arras while withdrawing. First to the lines built before the Battle of the Somme, and then to the Ancre, which forms a near-perfect killing ground as it is surrounded by several miles of wide open bog.
If the Germans choose to make Second Army the main spearhead, then, working from the closest point of their line, Second Army would have to advance 12 km per day. IOTL they managed only 5 km on the first day and about the same the second day. German operational plans had called for them to reach the British Artillery line and capture much of their heavy artillery (thus majorly reducing British combat potential) on the first day. They would never achieve this. Even this estimate is somewhat misleading as this distance represents the northern part of Second Army's line, which will have to act as flank guard against the Ancre before they get to Amiens, and is on the wrong side of the Somme, to boot. What we should be considering is the southern portion of Second Armies line which was over 70 km from Amiens. This would require them to be moving an average of 14 km per day, though the resistance would be less here, at the division between British Third and Fifth Armies. Either way, since Zabecki's sequential attack stratagem requires that Michael be executed without greatly impinging on Georg, Second army would have to go several times faster than they managed IOTL with less support.
Alternatively, The Germans could make Eighteenth Army the spearhead. This has the advantage of putting one of the Germans best formations against the weakest part of the British line. It also crosses some of the best terrain for maneuver along the whole front. This would effectively be what was done OTL, just with Eighteenth slightly more orientated to the North, along the South side of the Somme. The problem here is that Eighteenth Army has to advance an average of 16 km per day. They basically had all the same advantages of supply and reinforcement IOTL as they would ITTL and they only managed to average 11 km per day for that same 5 days.
No matter which method the Germans pick the tyranny of logistics is going to catch up with them. Generally in WW1, a logistics system can be expected to operate normally within 30 km of the railhead. In the Hundred Days offensives the Allied logistics system (probably the most effective the world had seen to that point, or at least a contender for the title) was able to operate 60 km from the Railhead with extensive mechanization and organizational reforms built around modern mobile warfare. IOTL on the 26th of March Eighteenth Army was operating 54 km from their railhead. The infantry had outrun their artillery and the artillery had outrun their ammunition supplies. In spite of the British and French basically setting up defences on the Avre at this point, and barely contesting the German advance further east, Eighteenth could only make 4 km that day. They would never regain their previous speed. ITTL, this limit would be hit sooner, and the results are probably going to be more acute due to the increased speed the Germans need to reach Amiens.
In short, I don't think the Germans have the capability to reach Amiens before the Allies can reinforce it. If they did, I don't think they could hold it, and even this would only come at the cost of shifting resources to Michael that would undercut Georg, which removes Zabecki's sequential attack from the board.
All of that is the first objection, my second is with this:
Were Hazebrouck to fall too, the British position on the continent would be untenable.
I readily admit I am not as sure of this one, as the first. I have not spent as much time looking into it. But the assumption tends to be that if the rail centres fall then the British must leave the continent. And I am not sure why to be honest. That GHQ was preparing contingency planning involving evacuation, I am well aware, but that does not mean that is the only option or the only one they considered. If Amiens and Hazebrouck fall then the British cannot direct supplies that land in one port to formations with supply chains running back to other ports. That much I understand. But I am not clear on why this means that each formation cannot be served by the rail lines from the Channel ports. This could end up amounting to 6 separate forces holding lodgments around 6 separate ports, but that does not seem impossible. And I think it would be the option that the BEF's political masters would go for, even if GHQ did not like it. While not as useful as the full BEF deployed as part of a contiguous line with the French Army, it would still force the Germans to keep forces facing West when they want to be going south.
And that is assuming that by the time that Hazebrouck is taken, that Amiens would not be back in Allied hands (if it were taken in the first place).
EDIT: fixed some grammar errors that were bothering me. Hopefully made it a little more readable.