Problems using artillery in the jungles of South East Asia in WW2

Hi all, I was pondering on the problems faced, using artillery in the jungles of South East Asia during WW2, and have a number of questions.

Firstly, are you defending or attacking that airfield, railway or road, or sea port, this has a major factor on your options. In defence, you may have had time to prepare, so guns and mortars can be positioned and potential targets registered, ammunition stockpiled, lines of communications laid down and improved, and crews given a modicum of creature comforts. In attack, everything has to be carried with you, and orientation can be very difficult the further into the jungle you venture.

Mobility; Moving your piece of artillery into position, and maybe late repositioning it. Firstly, use any river, rail line, road, or track, as far as you can, then what trails are available to move onto. Of course, as you get closer to your enemy’s defensive position, these lines of advance are going to quickly become heavily defended. So now its flanking movements, hacking through jungle. Can your artillery, positioned just off the river, rail, road or track reach the defensive positions or have they got to come as well, is so, your going to need pack mules. So, at this point, what guns/mortars do you need, weight is a big factor, does the gun break down into pack loads?

Supplies; Defence starts with an advantage, but even it will need resupply at some stage. Again, get back to those good avenues of movement as quickly as possible, the river, rail etc. but now its about how quickly supplies are consumed, so number of men to feed, how many rounds for the gun/mortar are being expended. Also, how heavy is each round, everything has to be carried. Which brings me to think of the next bit

Effectiveness of gun; A 2-inch mortar, is really light, use small rounds, easy to move, but not going to do much. However, what is? A 6-inch round will be more effective but the real measure is by weight, because everything has to be carried, so you get a lot of 2-inch rounds for one 6-inch round, you can be less accurate but still do better. Accuracy relies on observation, and in the jungle, the best observation has to be from the air, so how’s that air superiority coming along, are we a contested air space or worse still, operating under an enemy sky. Failing air observation, the defence would probably have the advantage here, using predicted fire and would be sitting on the higher ground, so may have some areas under observation.

So, what guns and mortars were successful, and why?

Did any army have an advantage due to their operational use of their artillery?

Were mortars more useful than gun/howitzers?

How critical was the pack animal to sustained operations?

Regards
Fatboy Coxy

 

..we had

....we had a thread similar to this a long time ago....also, I had a thread on arty/mortar use in the thick Hurtgen Forest
..I was in 81mm mortars....81mm mortars break down into 3 pieces: bipod/baseplate/sight..1980s bipod weighed 42lbs [ iirc ]...but was mobile ..we carried them everywhere..new bipods are lighter


..mortars are very effective/accurate/man-mobile!!/high angle = can hit just about anywhere--enemy in defilade
..I was in the weapons company which was battalion specific....so the bat. commander had 81mm on call for ''immediate'' fire..the rifle companies had 60mm so the company commander had 60mm for ''immediate'' fire
...the arty was not ready for ''immediate'' on call fire sometimes like the mortars are/were....

....the US had a great advantage I thought because they could concentrate many batteries for a ''single'' target...

..I wish I could find that thread on the Hurtgen Forest:
---FOs adjust fire by spotting rounds....if you are firing low angle arty rounds in the jungle or forest, the spotting rounds can hit trees--exploding prematurely to hitting the target/ground = poor accuracy ....
...if you are firing arty or mortars in the jungle/forest, the FOs have to have a good observation area:
1. trees and jungle can dissipate the impact--spotting rounds hard to see
2. trees and jungle can ''hide''/confuse exactly where the impact is
3. trees and jungle can ''hide'' the enemy-
4. the jungle can also dissipate mortar round impact
--if the FO is at elevation/away from the point troops, where he can get a good view of spotting rounds, he might not see where the enemy is
--if he is with the point troops, he can't see the spotting rounds clearly

..the other advantages for mortars:
--you can call them much danger closer compared to arty
--timed fire/timing for the battalion or company might be better coordinated since they are specific to those units and the men in those units know each other better...train together/etc..the units communicating are much closer than the arty would be...communications are more ''direct'' for mortars....


..my uncle fought in WW2 and he did not say much about the war...but one thing he said was , the Germans were very accurate with their mortars!..this tells you how effective mortars were and how the men had great respect for them
...with direct fire for mortars, you can put a round ''in a trashcan''..this is where the gunner can aim the sight directly on the target .....but, obviously this could not be used in the jungle/forest

.

 

Jungles of SE Asia and the SW Pacific present problems for artillery. Very short visibility. Hard to find good gun positions or OPs. Long communications and difficult ammunition resupply

So, what guns and mortars were successful, and why?
The British

The (British) Indian Army divisions were established for two regiments of 25 Pounder gun howitzers and one Mountain Regiment of 3.7" Pack howitzers. The 25 Pounder was a bit too heavy, long and wide for Jungle tracks. It had a decent range. The 3.7" Howitzer was mobile but its range was only 6,000 yards and outranged by the Japanese 75mm. The Australians cut down the 25 Pounder to make a Baby 25 pounder and in India the axle was shortened for Jungle trails.

The British 3" Mortar was fine,. but its range of 1500 yards inadequate. A stronger baseplate increased the range to 3,500 yards. 3 Mortars became the additional equipment of the anti tank units.

Were mortars more useful than gun/howitzers?

It depended on the task. High angle mortar fire was less likely to detonate in trees over own troops. However only field artillery had the range to mass fire. e.g. in the battle of the Admin box in Feb 1944 massed field artillery fire defeated the Japanese attempts to over run each brigade position. Mortars did not have the range to concentrate fire.

There was a technique to busting bunkers with indirect and direct fire. Use point detonating he to clear the brush. AP shot to penetrate any bursting layer then HE Fused delay to burst inside the bunker. 6" Howitzers and 5.,5" Guns were ideal. Mortars didn't have the weight of shell to do this.

How critical was the pack animal to sustained operations?

Mules were useful but human porters were often the only solution.

 

Hi Bronk7, the bit about problems in the Hurtgen Forest highlights the issues for artillery users very well.

With regard to the 60mm mortar, the Japanese used the 50mm Type 89 grenade discharger, or 'knee mortar' down at platoon level, and that provided immediate fire for them. I know the British had the 2-inch mortar, but dont know if it was well used in the jungle encounters at platoon or company level.

 

Don't forget the same situation during Vietnam...Artillery was key in many situations.