1/96 4.5"/19 (11.4 cm) 8cwt QF MKI Fore (MTB)

1/96 Scale Royal Navy 4.5"/19 (11.4 cm) 8cwt QF MKI Fore Gun x1 (Motor Boats). This is suitable for Fairmile D type Fast Motor Boats and/or Allied Coastal Patrol Boats (check your reference as boats carried different configurations). This Part is for the Forward Mount (the Mount base is angled to match the Deck). See My Shop for Aft Mount.

• 1x Mount in set
• Accurate Rivets, Hex Nuts, Training and Elevation Equipment, Sighting Equipment, Shell Stowage Rack
• Highly detailed and accurate parts, modelled from plans and photographic reference.
• Barrel printed separately and can be angled as desired with some alteration to hydraulic support. Shell Stowage Rack is also printed separately for ease of painting.

Historical Data
This weapon had an interesting history. It was originally designed to replace the spigot mortar used on Churchill AVRE tanks. However, the Army selected a 6.5" (16.5 cm) cannon in its place and development of this short-barrel 4.5" (11.4 cm) gun was halted. Then, in May 1944, the Navy was looking for a more powerful gun than the 6-pdr 7cwt in order to increase the hitting power of the MTBs of the Coastal Forces. Eighteen each of the 4.5" 8cwt gun and the Army's 95 mm (3.74") howitzer were ordered and comparison tests were performed at Shoeburyness against targets representing R-boats, sampans, armored barges and merchant ships. In the official report, the Navy concluded that the 4.5" (11.4 cm) gun was clearly superior and it was selected for further development.

Unfortunately, the very low muzzle velocity of this gun gave it a rather short range, about half of what was really desired, and shipboard firing trials with it were not very successful. Nonetheless, it was approved, although it did not enter service until long after the end of the war, and was used on MTBs and MGBs for the next fifteen years.

Constructed of barrel, removable breech ring and vertical sliding breech block with semi-automatic operation. The original naval order was for three prototypes and 106 guns. In September 1945 the Navy agreed to accept all 98 guns that had been finished, even though the requirement at that time was only 60 guns. A total of 36 Mark I mountings were actually completed along with a very few Mark II mountings.

Postwar, the British tried to develop a stabilized mounting for this weapon, designated as CFS-1 (Coastal Forces System Mark 1). The weight of this mounting grew alarmingly with "improvements" and did not see service use.

Actual bore length was 18.88 calibers. All British 4.5" naval guns have an actual bore diameter of 4.45" (11.3 cm).

Nomenclature note: CFS-2 was a stabilized mounting utilizing the 20-pdr (3.28" or 83.4 mm) Centurion tank gun. Although lighter than the CFS-1, it was still too heavy for coastal craft and did not see service use. Prototype was on Bold Pioneer, a photograph of which makes one wonder how the ship could be steered, as the gunhouse blocks much of the forward view.

Cleaning Information
Some part cleanup will be necessary. The 3D printing process uses a waxy substance to support certain part features during the printing process. Although the parts are cleaned by Shapeways, some waxy residue may remain.  It can be safely removed with water and a mild aqueous detergent like "Simple Green" using an old, soft toothbrush, Q-tips or pipe cleaners. During the printing process, liquid resin is cured by ultraviolet light. Microscopic bits of resin may remain uncured.

Let your parts sit in direct sunlight for a few hours to fully cure the resin.  
Water-based acrylic paints meant for plastics is strongly recommended. Other paints, especially enamels, may not cure on Frosted Detail 3D-printed plastics.
Use dedicated model sprue cutters to remove parts to minimise the risk of damage to parts.
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