O Group- Crossing the Strait of Johore

Below is an O Group scenario I've come up based on the Japanese 25th army crossing the Strait of Johore onto Singapore Island on February 8th 1942. 

 Background

 On Dec 8^th 1941 the Japanese 15^th army invaded Malaya and over the next two months drove the British, Indian and Australian forces of General Percival back towards Singapore. Disaster after disaster followed and on the 30^th of January the last battalion, the 2^nd Argyll and Sutherland Highlanders, led by their last remaining pipers marched across the causeway to “Fortress” Singapore.

The 22^nd Australian Brigade, 8^th Australian Division was responsible for defending the western coastline. Percival believed the Japanese would attack east of the causeway and his deployment reflected this. The 8^th division consisted of 6 weakened battalions  and each covered a front of “tidal mudflats and mangrove swaps intersected by stream and inlets, a defenders nightmare” (Thompson, 2005, p385). The three battalions of the 22^nd brigade covered a front of 16,000 yards, with the 2/20^th battalion holding 8,000 yards in front of the Kranji river and Sarimbun island.

On 1 February when Captain Gaven of A company 2/20^th arrived in their defensive positions on the position of the mangrove swamp he realised there were no fortifications or defences and no field of view of the enemy approach  (ibid, p389).

General Yamishita had outmanoeuvred  General Percival throughout the campaign and on the 8^th of February launched 16 battalions across the straits of Johore against the three battalions of the Australian 22^nd brigade on the Western side of the island.  At 8:15 in the evening 168 artillery pieces opened up on the Australian positions. The battle for Singapore had begun.

Mission:

Japanese: Destroy the Australian forces by inflicting 3 FUBARS (12 losses) on the defenders  or else get a platoon to successfully exit the table on the far side from the Straits of Johore.

Australians: Inflict 14 losses on the attacking Japanese forces will allow the Australians to withdraw in good order to positions further back in Singapore.

Deployment

The Australians are the defenders. The Japanese are the attackers.

It is assumed that platoons and combat patrols have landing craft and boats available but these can also be modelled if available.

 

Special Rules

Battalion dice: The Australians get 8 dice and the Japanese 9.

Defences: The Australians can deploy 3 units in trenches.

Night attack: The Japanese landed at about 8:45p. the entire game is played at night.

Johore strait: Units crossing the straits roll 2d6 and use the highest die (I assume the units have craft to cross the river, evne if not modelled on the table). 

Visibility: The maximum visibility for all units is 20”.

Australian Artillery Support: British communications broke down and although they had artillery support the British and Australian guns were not able to support the defending battalions. No artillery support is available for the Australians except for Battalion mortars.

Japanese artillery support: The Japanese get 2 artillery missions and no smoke missions.

Japanese Reserves: A full strength infantry company is available for turn 6 onwards on a 4+, check each turn till the company arrives).

Terrain

Mangrove swamps: Count as Rough terrain (RB p44) going. LoS can see a max of 1” into an area of mangrove. Likewise a unit in a mangrove swamp terrain feature can fire out of it if within 1” of the edge of the mangrove swamp.

Result

If the Australians win: They have blunted the initial attacks and delayed the Japanese advance enabling the battalion to withdraw in good order and are allowed 3 trenches and a hasty minefield in the next battle. 

Orders of Battalion

Australians

·       Worn battalion

·       2x MMGs

Japanese

·       Full strength Infantry battalion (confident)

·       1x MMG section

Japanese Reserves

·       1x Full strength infantry company (available on a 4+ turn 6 onwards, check each turn till the company arrives).

The Table

Historic Outcome

After intense fighting the forward positions of the three battalions of the 22nd brigade were overrun by the Japanese. Three companies of the 2/20^th battalion fell back to positions near Ama Keng village but the fourth company remained in its forward positions and was destroyed. The Japanese exploited the gaps in the thinly spread australain lines and by midnight the Japanese fired a sta shell to indicate they had secured their initial objectives. In confused fighting throughout the night the Australians were split into isolated parties and fell back across while the Japanese continued to drive inland. 

Night fighting rules

The following rules apply to fighting at night.

Spotting dice	Units are spotted on a following: 0-10”      4+ 10-20 “   5+
Max range	Units that did not fire can only be seen a maximum of 20” unless they fired in their previous turn.
Obscured	At night all targets count as obscured no matter if they are in cover/terrain or not and must use a spotting dice vs their target.
Direct fire to hit penalties	-1 FP to hit target at night with direct fire at ranges over 10”
Artillery HE penalties	-1d6 FP (represents not being able to see target accurately)

 

 Sources

·       Battalion diary: 2/20 Infantry Battalion Jan-June 1942 https://www.awm.gov.au/collection/C1366606

·       Thompson, P, (2005); The Battle for Singapore, Paitkus Books Ltd

·       Wikipedia: The Fall of Singapore