AHC: Successful defence of Rabaul in 1942

[La Rouge Beret]

Inspired by my earlier thread about successfully defending the Philippines, which can be found here.

With a POD in January 1941 how could Australia successfully defend the city of Rabaul and by extension New Britain island from the Japanese in 1942. Since it had an excellent harbour & two airfields at Lakunai & Vaunakanau, which were able to threaten the Japanese Caroline islands.

In the OTL a small garrison was sent in March 1941 consisting of an AIF Infantry Battalion, a local Militia unit, a New Guinea Volunteer Rifle, coastal defence battery, an anti tank battery & Field Ambulance. While the RAAF contingent included 10 CAC Wirraways (Texans in camouflage) & 4 Hudson light bombers.

There were apparently plans to construct a radar station & a defensive minefield, but neither option was exercised. While the cupboard is fairly bare in regards to available assets, but I thought that perhaps 21 or 453 Squadron could be detached from Malaya to New Britain. While I don't know about the possibility of obtaining a radar set or even deploying the 2/1st Independent Light Tank Squadron (originally slated to go to Malaya to New Britain).

Anyway, is there anything the ADF can do to ensure that New Britain remains in Allied hands or the campaign takes far longer then a single month.

 

[CV12Hornet]

Not really, there just aren't the resources available to stop what the Japanese brought to the party. There weren't enough troops to match the ad-hoc brigade the Japanese landed, and there certainly wasn't the aircraft nor capacity at Rabaul's air fields to do much about Akagi and Kaga parking themselves offshore.

 

[alspug]

Australia sent a few Wirraways to defend it from 2 carriers worth of the best aviators in the world. The odds of defending are zero with anything Australia had to offer.

 

[Carl Schwamberger]

Some how have a Brigade from the 3rd Marine Division arrive in mid December, with its composite air group and reinforced with a Base Defense Battalion . Have the Enterprise & Lexington and a robust cruiser group cover this. Such a event is near ASB, but while the Japanese can win the air battle they have unaffordable attrition to their carrier wings. They also have to fight a fairly well armed, disciplined, and trained ground combat formation. @ Wake the Japanese took embarrassing losses from a single Base Defense Battalion & one small fighter squadron. Complex and badly coordinated shoestring operations &Bamboo Spear tactics worked against undertrained and disciplined enemies. When the Japanese ran up against better trained ground forces and average or better enemy commanders, they tended to fail. Where the enemy lacked reserve and support repeated attacks would succeed, but as they found on new Guinea or Guadalcanal their success of beer days were not certain.

Bottom line is the only way here is to get a brigade of good soldiers on the ground, with artillery and more than token air support. US Marines, Australians, Patagonians, whoever. As long as they are trained and reasonably equipped.

 

[kmmontandon]

Von Funck gets chosen to lead the Afrikakorps, and is very conservative about it. This drastically reduces the Imperial demands for troops in North Africa, and at least one Australian division is never sent.

 

[La Rouge Beret]

Some how have a Brigade from the 3rd Marine Division arrive in mid December, with its composite air group and reinforced with a Base Defense Battalion . Have the Enterprise & Lexington and a robust cruiser group cover this. Such a event is near ASB, but while the Japanese can win the air battle they have unaffordable attrition to their carrier wings. They also have to fight a fairly well armed, disciplined, and trained ground combat formation.

I was talking with one of my former colleagues that has just completed staff college and that was damn near his answer. His response out of the box was a carrier group and or submarines to deter the amphibious threat.

@ Wake the Japanese took embarrassing losses from a single Base Defense Battalion & one small fighter squadron. Complex and badly coordinated shoestring operations &Bamboo Spear tactics worked against undertrained and disciplined enemies. When the Japanese ran up against better trained ground forces and average or better enemy commanders, they tended to fail. Where the enemy lacked reserve and support repeated attacks would succeed, but as they found on new Guinea or Guadalcanal their success of beer days were not certain.

I kept thinking about Wake as an example of how you could make an invasion particularly bloody for the Japanese. I'll have to go through the respective order of battles until I can see what else was in the cupboard at the time for the Allies.

 

[David Floyd]

What about 4th Marine Regiment? Ship it to Rabaul instead of Corregidor to join the troops already on Rabaul. Then, divert the Pensacola Convoy to Rabaul instead of Australia.

Not sure how workable that is.

 

[Draconis]

I'd have C Force, the Hong Kong bound Canadian Army brigade group which consisted of 2 infantry regiments and supporting units, redirected to Rabaul. Along with all their ship board supplies and ordnance some of which ended up in the Philippines in OTL. Maybe get a few Dutch or British submarines (working torpedoes) guarding the approaches hunting for IJN carriers. Whatever the Canadians may experience in New Britain it can't be any worse then Hong Kong. With time to prepare and train they would be very hard to over run quickly. How to do this? Perhaps it's decided that Australia needs more support? Or Skippy the space bat has developed a fondness for Maple candy?

 

[Carl Schwamberger]

4th Marines was grossly understrength & lacked anything heavier than a water cooled MG. A collection of rifle companies. They'd been shorted on training in their China guard duties. Well disciplined & with combat experienced officers & NCOs from the Banana Wars. Thats why I referred to full on Marine Brigade and a Base Defense Battalion. The 1930s Brigades had in addition to a rifle regiment:

Light artillery x12 75mm howitzers

Armored Car company

Engineer detachment- usually a reinforced company

AA Company of HMG

Brigade HQ with Communications unit.

Service group with supply company, automotive transport company, & other

Composite Air Group of 20 - 40 aircraft

The Base Defense Battalions were centered on 5" anti ship cannon & 3" Dual purpose AA & anti ship guns. Number of cannon varied varied by mission and availability. ie: on Midway they were reinforced with 7" naval guns. Also:

HMG AA company

Search light unit

Security company or oversized rifle company

Service/Supply/Construction unit.

Neither of these had a rigid TO & E. They were task organized by mission. ie: The Brigade deployed to Shanghai China in 1927-28 did not bring a Base Defense Battalion. The Brigade deployed to Iceland in 1942 did include one, & the air group was reinforced with USN air squadrons.

The trick is getting one together at the PoD date. Part of the 3rd Marine Division had been separated to stand up the Brigade in Iceland July 1941. Nominally there was components for another between the US west Coast and Hawaii, parts of the 3ed Marine Div. The 1st & 2d Marine Divisionswere on the Atlantic coast.

Keeping the reinforcements of the 'Pensacola Convoy together & delivering them to Rabaul is possible, but those were a mixed bag of random items & not a balanced or even coherent combat force.

 

[Cryhavoc101]

One of the IJN flattops suffers a mishap - anything from an accidental fire, a collision, to being sunk by a plucky submarine commander.

Whatever the cause she is off the table and the IJN leadership withdraws the 2nd flattop delaying the eventual invasion.

Additional forces (the suggestion of C-Force is a good one although both regiments were Cat C but might have far more time to carryout remedial training - most of the troops had never fired a BREN gun or operated a 2" Mortar before boarding their troop ships) manage to arrive including land based fighters and extra recce.

The forces on Rabaul manage to inflict a defeat on the landing force.

OTL it was often a company sized force trying to stop a Battalion sized force - sometimes with limited success until outflanked by the much stronger Japanese force - here it would be battalion sized verses battalion sized forces

And with the additional transport afforded by the C-Force (they had about 220 Carrier and trucks IIRC - most of which went to the Phillipines?) they are better able to respond to the various landings.

 

[Father Maryland]

I'd have C Force, the Hong Kong bound Canadian Army brigade group which consisted of 2 infantry regiments and supporting units, redirected to Rabaul. Along with all their ship board supplies and ordnance some of which ended up in the Philippines in OTL. Maybe get a few Dutch or British submarines (working torpedoes) guarding the approaches hunting for IJN carriers. Whatever the Canadians may experience in New Britain it can't be any worse then Hong Kong. With time to prepare and train they would be very hard to over run quickly. How to do this? Perhaps it's decided that Australia needs more support? Or Skippy the space bat has developed a fondness for Maple candy?

How well trained and equipped was C Force anyways?

 

[Cryhavoc101]

How well trained and equipped was C Force anyways?

My understanding is that both were Cat C - very low training completed - one of the units was picked for political reasons!

Both had many men who having only joined the units before they were sent had not fired a BREN gun which as you all know is the one thing a section would ensure that all members could do when they joined and the same with the 2" Mortar - the 2 principle weapons systems at Section and Platoon level.

Its officers were still not fully trained and its NCO core lacked experience - certainly in modern warfare.

Neither unit had completed any battalion level exercises.

However with the invasion of Rabaul not for another 3 months after they originally fought at Hong Kong (were they fought reasonably well and bravely against veteran IJA infantry) we could expect their performance to be better through many weeks of additional training alongside the slightly better trained Aussies.

 

[La Rouge Beret]

What type of political changes would be necessary for C Force to be diverted to Rabaul? Plus if they are diverted is it likely that they would remain in theatre for the duration of the Pacific campaign?

 

[Father Maryland]

My understanding is that both were Cat C - very low training completed - one of the units was picked for political reasons!

Both had many men who having only joined the units before they were sent had not fired a BREN gun which as you all know is the one thing a section would ensure that all members could do when they joined and the same with the 2" Mortar - the 2 principle weapons systems at Section and Platoon level.

Its officers were still not fully trained and its NCO core lacked experience - certainly in modern warfare.

Neither unit had completed any battalion level exercises.

However with the invasion of Rabaul not for another 3 months after they originally fought at Hong Kong (were they fought reasonably well and bravely against veteran IJA infantry) we could expect their performance to be better through many weeks of additional training alongside the slightly better trained Aussies.

Sending a Brigade to Hong Kong by that point was pure foolishness. Obviously indefensible with the forces the Empire had in the region and other commitments. I mean yeah some sort of tripwire force made sense but you could do that with a regiment or Batallion backed by local Militia.

Sending a Brigade was just a waste.

 

[Father Maryland]

What type of political changes would be necessary for C Force to be diverted to Rabaul? Plus if they are diverted is it likely that they would remain in theatre for the duration of the Pacific campaign?

The Brits realize that come war Hong Kong is indefensible and while a tripwire force is needed a Brigade is a waste. So a batallion gets sent instead.

 

[La Rouge Beret]

The Brits realize that come war Hong Kong is indefensible and while a tripwire force is needed a Brigade is a waste. So a batallion gets sent instead.

Completely agree.

 

[David Floyd]

4th Marines was grossly understrength & lacked anything heavier than a water cooled MG. A collection of rifle companies. They'd been shorted on training in their China guard duties. Well disciplined & with combat experienced officers & NCOs from the Banana Wars. Thats why I referred to full on Marine Brigade and a Base Defense Battalion. The 1930s Brigades had in addition to a rifle regiment:

Light artillery x12 75mm howitzers

Armored Car company

Engineer detachment- usually a reinforced company

AA Company of HMG

Brigade HQ with Communications unit.

Service group with supply company, automotive transport company, & other

Composite Air Group of 20 - 40 aircraft

The Base Defense Battalions were centered on 5" anti ship cannon & 3" Dual purpose AA & anti ship guns. Number of cannon varied varied by mission and availability. ie: on Midway they were reinforced with 7" naval guns. Also:

HMG AA company

Search light unit

Security company or oversized rifle company

Service/Supply/Construction unit.

Neither of these had a rigid TO & E. They were task organized by mission. ie: The Brigade deployed to Shanghai China in 1927-28 did not bring a Base Defense Battalion. The Brigade deployed to Iceland in 1942 did include one, & the air group was reinforced with USN air squadrons.

The trick is getting one together at the PoD date. Part of the 3rd Marine Division had been separated to stand up the Brigade in Iceland July 1941. Nominally there was components for another between the US west Coast and Hawaii, parts of the 3ed Marine Div. The 1st & 2d Marine Divisionswere on the Atlantic coast.

Keeping the reinforcements of the 'Pensacola Convoy together & delivering them to Rabaul is possible, but those were a mixed bag of random items & not a balanced or even coherent combat force.

Agreed with all of that. I was trying to think of forces that were available and in theater. A full Marine Brigade w/ base defense battalion obviously would be better, but as you say, the trick is getting them together in time.

I also like the C Force suggestion, with a POD of their transport suffering an engineering casualty and still en route on 12/7.

 

[Cryhavoc101]

Sending a Brigade to Hong Kong by that point was pure foolishness. Obviously indefensible with the forces the Empire had in the region and other commitments. I mean yeah some sort of tripwire force made sense but you could do that with a regiment or Batallion backed by local Militia.

Sending a Brigade was just a waste.

They came very close to withdrawing the forces they had and not reinforcing with any troops!

Keeping a reduced brigade based around a reinforced HK Volunteers should have worked - enough to show the flag and destroy anything useful before lowering it.

In the end they had 14,000 men there!

 

[Cryhavoc101]

I would add that the idea of sending Canadian troops to Hong Kong was to show the Japanese that there was an international aspect to invading the place.

We up timers sitting secure in our armchairs in 2021 might scoff now but this approach is still used to this day and at the time the Canadian government believed that it would effectively give the Japanese pause.

The C Force Brigade was not actually expected to have to fight.

No one really appreciated how nuts the Japanese were!

 

[jsb]

I would add that the idea of sending Canadian troops to Hong Kong was to show the Japanese that there was an international aspect to invading the place.

I get sending say US marines might change things and introduce a level of international challenge, but did anybody think that Canada would not fight if GB was attacked, after all they are already fighting together in Europe by 41......?