Table of Contents
How do you use a poker gauge?
The poker gauge is placed between the last and second last stern tube seals (aft- near the propeller). The reading is taken every dry dock and recorded. A hole is provided on top of the seal which is closed by a plug. This plug is removed, the poker gauge is inserted and a reading taken.
How is propeller drop measured?
Now due to the weight of propeller and the clearance developed due to wear , the shaft will come down by a certain amount. This drop in propeller shaft is termed as propeller wear down or propeller drop. Propeller drop is measured by POKER GUAGE during dry dock.
What is tailshaft survey?
1.1 Tail-shaft survey means survey of propeller shafts and tube shafts (hereafter referred to as tail-shafts) as well as survey of other propulsion systems.
What type of gauge is needed to check the diameter of propeller shaft?
Poker gauge is one unique tool among different types of measuring instruments is available in mechanical or digital form on ships. It is only used for one purpose; To measure propeller stern shaft clearance, also known as propeller wear down.
What is rope guard?
Rope guards are the protection barrier for propeller shafts shielding them against line entanglement around main shafts. Typically rope guards are attached by means of welding or bolted with locking wires in place.
How do I know if my stern tube is wearing down?
Stern Bearing Wear-down Measurement:
- Use Poker Gauge or Wear down Gauge or Vernier Caliper.
- Remove Rope Guard.
- Take out Check Plug and Drain Plug.
- Turn Tailshaft until ‘0’ marks on periphery of aft chrome steel liner flange and mating marks on Simplex seal and Sterntube are in line.
What is pintle in rudder?
A pintle is a pin or bolt, usually inserted into a gudgeon, which is used as part of a pivot or hinge. Other applications include pintle and lunette ring for towing, and pintle pins securing casters in furniture.
How many years when the tail shaft must be drawn?
(b) Except as provided in paragraphs (c) through (f) of this section, each tailshaft on a vessel must be examined twice within any 5 year period. No more than 3 years may elapse between any 2 tailshaft examinations. (c) Tailshafts on vessels fitted with multiple shafts must be examined once every 5 years.
How do I prepare a boiler for a survey?
Open all manhole, handhole and mudhole doors and allow boiler to ventilate. Plug the blow down pipe to avoid dirt and sludge blocking it. Thoroughly clean the boiler internally remove any scale and clean the tubes internally and externally prior to inspection.
How many types of gauges are there?
All gauges can be divided into four main types, independent of their actual use.
What is the type of gauge?
Plug Gauges : These are used for checking holes of many different shapes and sizes. Ring Gauges : External diameter measuring gauges. Taper Gauges : Taper testing gauges. Snap Gauges : These are used for checking shafts.
Are propellers screws?
Most marine propellers are screw propellers with helical blades rotating on a propeller shaft with an approximately horizontal axis.
Where is the poker gauge on a dry dock?
>Water cooled bearing clearance = 8mm. >Oil cooled bearing clearance = 2mm. > The poker gauge is placed between the last and second last stern tube seals (aft- near the propeller). >The reading is taken every dry dock and recorded. >A hole is provided on top of the seal which is closed by a plug.
How does a poker gauge measure propeller drop?
>A hole is provided on top of the seal which is closed by a plug. >This plug is removed, the poker gauge is inserted and a reading taken. > So since the propeller is connected to the shaft and the poker gauge measures how much the shaft has ‘dropped’ due to the wear down of the bearing on which the shaft runs.
How do you take a poker gauge measurement?
In order to take the measurement, we need to have access through the rope guard. There are different access plates (open/accessible, bolted, and welded). Also, Special equipment needs to be provided from the Chief Engineer onboard, since each vessel has specific customized tools (poker gauge).
What is the poker gauge on stem tube bearings?
NOTE: When stem tube bearings are renewed or re-metallic, clearances will be back to original. On refit, it is essential that these clearances are recorded and also the corresponding new poker gauge readings for future comparison. With most modem stem tube seal designs, the poker gauge measures from the seal box “OD” to the seal sleeve “OD”.