A bit of a pun - light bombers like the Ju-88 or Blenheim had relatively light armament, often 1-2 light machine guns able to be brought to bear on any attacking fighter. How effective were they? One could argue that the most significant difference is between any defensive fire and none at all. AFAIK the fast Mosquito was the only widely-used bomber to dispense with defensive guns. The few guns would naturally be disposed to cover the best attacking postions, mainly from behind; there were often also flexible guns in the nose. Inevitably there were considerable blind spots, although this could be somewhat obviated by flying in formation for mutual defense. The guns and their ammunition were also light in weight, and they were often manned by crewmen like radio operators who had to be carried anyway, but there would still be some impact on bombload or performance. The consensus in WWII seems to have been that bombers needed at least the basic defensive weapons - what do we think?
When most of the war's light and medium bombers were designed....air forces around the world were STILL working on the lessons of WWI, that rifle calibre MGs were enough to keep off attacking fighters. Remember, they didn't have to shoot fighters down - "just" make it hard enough to keep a bead on the bomber target long enough for enough solid bullets in the bullet path to intersect with something vital enough to keep the bomber in the air The Spanish Civil War had proved the concept that "the bomber would always get through" - because it did!...simply because the majority of figthers involved in it were still using a 2x or 4xMG armament, and thus were really no more effective than WWI fighters. Likewise the early WWII experience for the first fighters the LW encountered were lightly armed Polish fighters. In fact - there were plenty of unescorted LW bomber raids right up to and including the BoB. Also - those early "box formations" of light and medium bombers DID work; at least two Hurricane pilots lost their lives during the early weeks of the BoB when they broke into Do17 formations, contrary to standing orders.
help me would probably be the statement with a bit of trash talk during the day when an opposing fighter is on your tail. same could be said of the night time air actions of LW NF's defending agasin the wily Mossie crew in 44-45. though the single MG 131 was successful at times to ward off the Allied NF to make a quick down to the earth escape and even partially successful as an attacking weapon underneath a BC 4-engine bomber when the SM 2cm ammo had run out or jammed according to LW NF crews.
Interesting thread topic. I'd love to hear from Shortround6 on this, he a member here? One thing to keep in mind is the fast medium bomber was an interwar revolution brought about by the highly successful Soviet SB bomber. Rather than build lumbering four engine bombers like the Tupolev, the Soviets tried a clean, twin engine high speed aircraft with range and bombload requirements. Defensive armament was secondary because the idea was to fit the latest aero engines and outrun interceptors over their own territory. This actually worked in Spain, and the SB was a success. It influenced ideas on successful tactical air deployment in europe. Both Britain and Germany answered with their own "fast bomber" designs (Dornier and Blenheim), more to it than that but I'm giving the curt version. The US was still going with a more traditional strategic air fleet, and Bomber Command was essentially splitting their bets building Blenheims and Defiants and things like that, for continental and overseas "medium value, fast striking" operations. The Ju-88 actually managed to achieve these basic archetypteral requirements for a short period over England, I've accounts of MkI Spits having a terrible time trying to catch the fast Junkers on egress. Part of the reason Mölders and others complained about close fighter escort, it was decidedly only helpful to bomber crew moralé and is recognised by most vets postwar as otherwise superfluous given the circumstances. The fast bomber strategy was actually working with the Ju-88 for a bit there in 40-41, they didn't really need an escort, at the very least no more than free ranging escort. Point being medium bombers aren't designed for a medium bomb capacity. They're more correctly called "fast bombers" and are designed to outrun intereptors. After that they become tactical strike aircraft, bombers are of little strategic value unless they can function in contended airspace. Heavy bombers are designed to be heavily armed. Some heavy bombers, like the Wellington have two engines, they're just really sturdy and quite well armed. Loadbearing, overall isn't the primary distinction between medium and heavy bombers. Their different roles more describe it I think. And how they're armed is how best suits the role. First thing they do on maritime variations of German bombers is start slapping 2cm cannon and 13mm MG all over them. But it's not for the medium bomber role anymore, it's for maritime strike.
Hi Vanir - I'm not so sure how safe it is to say the SB influenced others to develop their own twin-eingined fast mediums...for Bristol certainly had what would become the Blenheim on their design tables at the same time And certainly none of the major aviation leaders waited until the SCW to start developing them! Bristol for instance had been working on their Type 135 in 1933... As for Bomber Command , I think you mean the Blenheim and the Fairey Battle; Hooton makes the point that in both cases they were "culminations" of a number of different historical trends in the RAF - being seen as updated versions of the aircraft that the Bristol Fighter had been in WWI, a two-seat light bomber that was as fast and as capable as most fighters The Blenheim was seen as a replacement for all those Hawker single engined fast bombers of the early 1930s that turned out to be as fast as Fighter Command's biplane fighters, and the Battle was seen as sticking closer to the "corps" role of Army Coop/light tactical bombing while still filling that Bristol Fighter niche. Why two when the Battle was so ...crap...and the Blenheim was so fast, had the same defensive armament and took up the same number of crew? Interwar British aero companies were quite small, and the government liked to spread the "jam" around to keep design teams working and together, hence the multiplicity of fighter types and medium bomber types we "enjoyed" in the mid-'30s. Also, like using "I" tanks to equip tank regiments post-Dunkirk to at least get them formated and exercising because at least the Matilda and Valentine were in production while new cruisers were still around the corner...the Battle was only supposed to be a transitional design as the Air Plan of the second half of the 1930s worked out, to give something for those newly-forming RAF squadrons to actually fly. The traditional story is that then, in a panic after Munich, the Cabinet forced a re-jig of the Air Plan to ensure that Fighter Command was complete as per the original phased Air Plan...but this came at the expense of backpedalling a lot of the Bomber Command development; no Blenheim or Battle replacements (thank god for De Havilland!), not enough multiengined bomber crew trainers, and not enough money for Coastal Command - hence at the start of the war it had to borrow even BC's Ansons and Oxfords for maritime patrol!...and the RAF didn't organise a Bomber Command nightflying school until the late spring of 1939... Did you ever get to read John James' The Paladins?
This brings up a follow-on question, the distinction between light and medium bombers. As Vanir points out, twin-engine planes like the Wellington were originally designated as heavies, to distinguish them from lights like the Blenheim. 'Medium' came about to distinguish them from four-engine heavies. Only two WWII air forces used four-engine bombers in large numbers, and AFAIK 'medium' was only a formal designation in the USAAC/F. A rough working definition might be that a medium functions similarly to a heavy. B-26s and Wellingtons flew many of the same missions as B-17s and Lancasters - literally the same missions in Bomber Command. Medium bombers' armament often resembled that of heavies, with features like tail gun positions and turrets. Of course there are myriad variations. The Luftwaffe did strategic bombing in the Battle of Britain/Blitz with Do-17s and Ju-88s. B-25s were just as likely to be found strafing at treetop level as bombing in formation from altitude. Still, to the extent that there is or needs to be a distinction, it would appear to be that light bombers are tactical strike aircraft and mediums are more like twin-engine heavies.
It's slightly more complicated than that; the best way of looking at what pigeonhole the Air Staff in the UK put a given aircraft in is to look at the original Air Ministry specifications The Handley Page Hampden for instance grew out of B.9/32....for a "Twin-engine medium day bomber with appreciably higher performance than predecessors..." The HP Heyford grew out of B.23/32...for a "Twin-engine medium bomber" B.29/33 and the related B.23/34 gave us the BP Sidestrand/Overstrand for a "Twin engine medium day bomber with power-operated nose turret" B.1/35 rsulted in the Vickers Warwick as a "Twin-engine medium bomber"...while B.21/35-B.20/36 resulted in the A.W. Whitley as a "Twin-engine medium bomber" The Wellington originated from B.9.32 for a long-range medium bomber - it was the Short Stirling that was a specifically designated as a "heavy", it originating from B.12/36 for a "Four-engine heavy bomber". For various reasons it fulfilled the same role/missions as the Stirling...but was definitely known in the Air Ministry as a "medium", as was the under-development Avro Manchester.
Since the USAAF classified the A-20 as a 'light' bomber, it makes IMO more sense to use the number of engines as a guideline. Generally the more engines, the bigger the plane and the more damage it can take. Of course actual size and date of design needs to be taken into consideration as for example both a B-26 and a Bristol Blenheim had two engines. Also didn´t classification change over time? The Wellington and Whitley started as heavies and were later downgraded to mediums. The only thing I can say for sure is that any bomber with one engine belongs into the 'light' category. With regard to your initial question: Depends on what is attacking you. If it’s a Japanese fighter RCMG are ok, if it´s a Spitfire, Me109 or P-40 a 50 cal. is preferable. In case the attacker is a twin engine heavy/night fighter 50 cal. it has to be.
As noted above- that wasn't the case. What happened was they were grouped into the "heavy bomber force", the RAF's strategic bombing capacity - and were grouped with heavy bombers like the Stirling. But they were specified, ordered and paid for as "mediums". Had the events of late 1939 not shown early that the Wellington was useless at the daylight tactical role it was expected to fulfill too - god knows what it would have been asked to do
