Overview The Dual Trolley Crane moves containers on and off a ship in sets of two. They are often paired with a [crane gang](CraneGang.html) to transport the containers into the yard. Dual Trolley Cranes are added to the model in the [Berth Layout tab](Berth_Layout.html) of the Berth Planner. They can gantry (move) along the edge of the berth from one ship to another so long as they are not blocked by another crane or a [crane allocation barrier](Berth_Layout.html#cranebarrier). After including one or more dual trolley or single trolley cranes in the model, you can click on an individual crane to make detailed changes to that particular crane. This way you can represent the faster movement of a newer crane or the slower movement of an older one. Properties - Land Side/Water Side Trolleys  Name - This value is the name assigned to the crane object. 聽聽聽 聽聽聽 聽聽聽 Determine Moves - This dropdown box determines how the crane's movement is calculated. Options include:- "Based on Time Per Move" - The crane's movements are separated into three categories: discharges, loads, and dual cycling. Each of these categories is assigned a different expression for calculating the move time. When the crane moves, it calculates the movement time based on the appropriate category, then splits its gantry, trolley, and hoist movements across the calculated time. - "Based on Crane Speeds" - The crane's gantry, trolley, and hoist movements are handled separately and are based upon speed values assigned by the user and actual distances represented in the model. This method provides no variability for a given move since each move is based strictly on the assigned speeds. Based on Time Per Move  Time Per Move for Discharges - This value is the time it takes to unload a container from the ship. This value may be adjusted by the [speed tag](Hatch_Profiles.html#SpeedTag)on the Hatch Profiles tab of the Berth Planner. Time Per Move for Loads - This value is the time it takes to load a container onto the ship. This value may be adjusted by the [speed tag](Hatch_Profiles.html#SpeedTag)on the Hatch Profiles tab of the Berth Planner. Time Per Move for Cycling - This value is the time it takes to perform a discharge followed immediately by a load. This value may be adjusted by the [speed tag](Hatch_Profiles.html#SpeedTag) on the Hatch Profiles tab of the Berth Planner. Moves Per Hour Conversion Tool - This widget is a tool for converting moves per hour into minutes per move. Most modelers think about yard equipment in terms of moves per hour, but the model requires values in terms of minutes per move. Using this tool, you can easily integrate the correct values into the expressions above. Gantry Speeds - This value is the speed that the crane travels when moving along the berth from one ship to another. Note: To represent the correct speed for twin lift, the [speed tag](Hatch_Profiles.html#SpeedTag) on the Hatch Profiles tab of the Berth Planner should be changed. An appropriate value might be about 1.9 (not quite 2 due to the extra time to latch both containers). Based on Crane Speeds  Lift Height - This value is the height to which the crane's hoist will be lifted. Length units are determined by the [Model Units window](Model_Units.html). Lift Hoist When Idle - This checkbox helps the crane be more efficient while it is waiting for a truck. If this box is checked, then the crane will lift its hoist (with a container in tow) while it is waiting, so that it is ready to move when the truck arrives. If this box is unchecked, the crane will wait until the truck arrives before moving. Travel Sequence - This value allows you to edit the sequence of movement events for the crane. Options are listed to the right. The default sequence is to lift, trolley, and then drop. Speeds - This set of values are the various speeds of the crane. Each movement is handled separately. If the acceleration or deceleration are 0, then the crane will instantly move at top speed or stop completely without any acceleration or deceleration time. Time and length units are determined by the [Model Units window](Model_Units.html). Dual Trolley Tab  Trolley Combination - This combobox allows you to choose between the different types of trolley combinations: single or tandem lift for the water side trolley. Platform Slots - The number of containers that may be placed on the platform, one or two. 聽This is only a valid option when the Trolley Combination is set to Single - Single, since any聽other option requires two slots. Platform Delay Time - The amount of time it takes for the container on the platform to be checked. 聽Edit the code to create a distribution. Tandem/Single - The amount of time it takes for the trolley to switch from tandem to single lift. 聽Edit the code to create a distribution. Platform Height - The height of the platform from ground level. Platform Location - The distance from the water side edge to the beginning of the聽platform. Platform Width - The width of the platform. Tandem Settings - This block has settings for the tandem operations. It will not affect Dual Trolley Crane operations if no tandem trolley. - Tandem Discharges % - Percentage that represents the possiblity of doing a tandem discharge lift. - Tandem Load % - Percentage that represents the possiblity of doing a tandem load lift. Trolley and Hoist Tab  The Trolley and Hoist Properties for each side of the Dual Trolley Crane can be edited by pushing their respective Properties buttons.聽 The Crane's Properties can be edited on the [General](Flexsim_Users_Manual.html) tab. Landside Hoist Lift Height -聽This is the highest position that landside spreader can be lifted. Waterside Hoist Lift Height -聽This is the highest position that waterside spreader can be lifted. On State Change - This trigger is fired when a dual trolley crane is changing to the next state. You may use the trigger to fire your own logic when the crane's state is about to change. The parameters that passed into this trigger are as follows: - param(1) is an integer that represents the state the crane will change to. - param(2) is the state profile number. For dual trolley cranes, 1 means the crane; 2 means the landside trolley; 3 means the waterside trolley. The trigger can return an integer value. Return values may include: - By default, the trigger will returns a 0, and FlexTerm will change the crane's state based its default logic. - If the trigger returns -1, FlexTerm will not change the crane's state, instead it will leave the crane in its previous state. - If the function returns a positive number, the state will be changed to this new state number. - The following macros of quay crane states should be used as return values if the profile is 1, i.e. the crane: - QUAY\_CRANE\_STATE\_IDLE: crane has no work to do. - QUAY\_CRANE\_STATE\_PRODUCTIVE: crane/trolley is on productive moves - QUAY\_CRANE\_STATE\_MOVING\_TO\_HATCH: crane is moving to a hatch - QUAY\_CRANE\_STATE\_WAITING\_DURING\_DISCHARGE: crane is waiting for horizontal transport - QUAY\_CRANE\_STATE\_WAITING\_DURING\_LOADING: crane is waiting for horizontal transports during loading operation - QUAY\_CRANE\_STATE\_SETUP: crane is at setup state (as defined in hatch profile) - QUAY\_CRANE\_STATE\_WAITING\_PLATFORM: crane is waiting for platform (dual trolley crane only) - The following macros of quay crane states should be used as return values if the profile is 2 or 3, i.e. the landside trolley or the waterside trolley: - TROLLEY\_STATE\_IDLE: trolley has no work to do. - TROLLEY\_STATE\_DOING\_DISCHARGE: The trolley is on productive moves to discharge containers. - TROLLEY\_STATE\_DOING\_LOAD: The trolley is on productive moves to load containers. - TROLLEY\_STATE\_CONFLICT\_WAITING: The trolley is waiting for platform or the other trolley due to conflicts. - TROLLEY\_STATE\_WAIT\_FOR\_LOAD: The trolley is waiting during load operations. - TROLLEY\_STATE\_WAIT\_FOR\_DISCHARGE: The trolley is waiting during discharge operations. 聽聽聽 聽聽聽 聽聽聽 聽Please refer to the sample code in the trigger for an example.  Operation Trigger - This trigger is fired when the Dual Trolley Crane's landside trolley or waterside trolley reaches a specific moment during dicharge or load operation. The parameters that passed into this trigger are as follows: - param(1) is a treenode that represents the current Dual Trolley Crane which owns this trigger. - param(2) is an integer macro that represents the operation type that specifies the operation status of the current Dual Trolley Crane's landside or waterside trolley. For landside trolley operations, the following macros of Dual Trolley Crane operation types will be passed as param(2): - DT\_CRANE\_OP\_LS\_DISCHARGE\_PICKUP\_BEGIN: the LS trolley begins moving to pickup the discharge container(s) from the platform. - DT\_CRANE\_OP\_LS\_DISCHARGE\_DROPOFF\_BEGIN: the LS trolley begins to drop off the discharge container(s) to vehicles or ground after pick-up. - DT\_CRANE\_OP\_LS\_DISCHARGE\_FINISH: the LS trolley finishes discharging the container to vehicles or ground. - DT\_CRANE\_OP\_LS\_LOAD\_PICKUP\_BEGIN: the LS trolley begins moving to pick up the load container(s) from vehicles or ground. - DT\_CRANE\_OP\_LS\_LOAD\_DROPOFF\_BEGIN: the LS trolley begins to drop off the load container(s) to the platform after pick-up. - DT\_CRANE\_OP\_LS\_LOAD\_FINISH: the LS trolley finishes loading the container(s) to the platform. For waterside trolly operations, the following macros of Dual Trolley Crane operation types will be passed as param(2): - DT\_CRANE\_OP\_WS\_DISCHARGE\_PICKUP\_BEGIN: the WS trolley begins moving to pickup the discharge container(s) from the ship. - DT\_CRANE\_OP\_WS\_DISCHARGE\_DROPOFF\_BEGIN: the WS trolley begins to drop off the discharge container(s) to platform after pick-up. - DT\_CRANE\_OP\_WS\_DISCHARGE\_FINISH: the WS trolley finishes discharging the container(s) to the platform. - DT\_CRANE\_OP\_WS\_LOAD\_PICKUP\_BEGIN: the WS trolley begins moving to pick up the load container(s) from the platform. - DT\_CRANE\_OP\_WS\_LOAD\_DROPOFF\_BEGIN: the WS trolley begins to drop off the load container(s) to the ship after pick-up. - DT\_CRANE\_OP\_WS\_LOAD\_FINISH: when the WS trolley finishes loading the container(s) to the ship. - param(3) is an integer that represents the total number of containers involved in the current operation. By default, the max number of containers per move is 4. - param(4) is an integer that represents the first container's containerid in the current operation. 聽聽聽聽聽聽聽聽聽聽聽聽 If the first container doesn't exist, the containerid value will be 0. - param(5) is an integer that represents the second container's containerid in the current operation. 聽聽聽聽聽聽聽聽聽聽聽聽 If the second container doesn't exist, the containerid value will be 0. - param(6) is an integer that represents the third container's containerid in the current operation. 聽聽聽聽聽聽聽聽聽聽聽聽 If the third container doesn't exist, the containerid value will be 0. - param(7) is an integer that represents the fourth container's containerid in the current operation. 聽聽聽聽聽聽聽聽聽聽聽聽 If the fourth container doesn't exist, the containerid value will be 0. 聽聽聽 聽聽聽 聽聽聽 Please refer to the sample code in the trigger for an example.  Appearance: 3D Shape - This dropdown box is for users to choose the Dual Trolley Crane's 3D model - Simple DualTrolleyCrane: a simple Dual Trolley Crane 3D model with no other components. - Standard DualTrolleyCrane: a standard Dual Trolley Crane 3D model with more detailed components. Note:聽After switching appearance, users might need to adjust crane position, platform position, trolley positions and liftheights. Too many detailed models will slow down the simulation. Use Transfer Points - Checkbox to enable ground transfer point editor. If this is unchecked, transfer point editor will be disabled. Note:聽this is only useful when crane is working with strad gang. Number of Transfer Points - The total number of transfer points. Refresh Transfer Points - Click this button to refresh transfer point table below based on the input in "Number of Transfer Points".聽 Note:聽In the transfer point table, user is expected to input transfer point center's y location in crane space. The (0, 0, 0) point in crane space is located in the upper left bottom corner of crane. That is why the sample inputs in the above image are negative values. Additional Details  One of biggest resources in a port is the crane. When a crane is working on a ship, it should be constantly busy. However, if there are not enough trucks to service the crane, then the crane will be idle part of the time. FlexTerm provides a visual indication of this by drawing a red box under an idle crane. Additionally, FlexTerm gathers statistics on how often each crane is waiting so you can figure out how many trucks are needed to service that crane.