**What type of rock did the engineers encounter when constructing the Bergen Hill Tunnels?**

- Sandstone
- Limestone
- Diabase
- Granite

Correct Answer: Diabase

Correct Answer Explanation: The Bergen Hill Tunnels passed through a trap dike, which is a geological formation where igneous rock has intruded into sedimentary rock. Diabase, also known as trap rock, is a type of igneous rock commonly found in trap dikes.

**What innovative drilling technique was used to speed up excavation in the Bergen Hill Tunnels?**

- Using explosives
- Using a single drill per heading
- Using multiple drills per heading
- Using hand tools

Correct Answer: Using multiple drills per heading

Correct Answer Explanation: To increase excavation speed, the engineers employed multiple-drill headings, with as many as eight drills working simultaneously. This technique allowed them to drill multiple holes at the same time, significantly reducing the overall drilling time.

**What was a major challenge encountered during the construction of the Bergen Hill Tunnels?**

- The tunnels were too short
- The tunnels were too long
- There was a lack of materials
- Ventilation was poor

Correct Answer: Ventilation was poor

Correct Answer Explanation: Smoke from blasting and locomotives created a significant ventilation challenge, especially in the Hackensack tunnel with its ascending grade. The engineers employed a series of fans and blowers to improve air circulation and mitigate the smoke and fog issues.

**Which of these methods was NOT used to construct the Bergen Hill Tunnels?**

- Cut-and-cover method
- Center top heading method
- Drill and blast method
- Shaft sinking method

Correct Answer: Cut-and-cover method

Correct Answer Explanation: The Bergen Hill Tunnels were constructed using the center top heading method and the drill and blast method. The cut-and-cover method, where an open trench is excavated and then covered with a roof, is typically used in shallower tunnels or for underground structures where excavation is done from the surface.

**What did engineers use to move concrete buckets to the platform above?**

- Cranes
- Conveyor belts
- Hoists
- Traveling gantries

Correct Answer: Traveling gantries

Correct Answer Explanation: Traveling gantries were used to hoist concrete buckets from rail cars to the platform above, allowing for efficient placement of concrete in the arch and bench walls.

**What geological feature presented a challenge to the construction of the Bergen Hill Tunnels?**

- A fault zone
- A sinkhole
- A landslide
- A cave

Correct Answer: A fault zone

Correct Answer Explanation: The tunnels pass through a fault zone for nearly 400 feet, presenting challenges due to unstable ground and requiring extensive timbering.

**How was water-proofing achieved in the Bergen Hill Tunnels?**

- Using a layer of concrete
- Using a layer of asphalt
- Using layers of felt and pitch
- Using a layer of clay

Correct Answer: Using layers of felt and pitch

Correct Answer Explanation: To prevent water infiltration, the tunnels were water-proofed using six-ply felt and seven layers of pitch, especially in the wet sections near the river.

**What was the average time required to drill a 10-foot hole in the hardest trap rock encountered in the tunnels?**

- 2 hours
- 5 hours
- 10 hours
- 20 hours

Correct Answer: 10 hours

Correct Answer Explanation: The hardest trap rock encountered in the tunnels had a specific gravity of 2.98, making it extremely difficult to drill. The average time to drill a 10-foot hole in this rock was almost 10 hours.

**What was the primary method of excavation used for the Bergen Hill Tunnels?**

- Cut-and-cover method
- Shield method
- Drill and blast method
- Trench method

Correct Answer: Drill and blast method

Correct Answer Explanation: The Bergen Hill Tunnels were excavated using the drill and blast method, which involves drilling holes into the rock and then using explosives to break it up.

**What was the average progress per working day in each of the Bergen Hill Tunnels?**

- 2 feet
- 4 feet
- 6 feet
- 8 feet

Correct Answer: 6 feet

Correct Answer Explanation: The average progress per working day in each tunnel was 6.26 feet.

**How many days were worked on the Bergen Hill Tunnels in total?**

- 200 days
- 500 days
- 940 days
- 1,500 days

Correct Answer: 940 days

Correct Answer Explanation: The total number of days worked on the tunnels was 940 days.

**What was the primary cause of lost time during the construction of the Bergen Hill Tunnels?**

- Lack of funding
- Labor strikes
- Equipment failures
- Delays by the Receiver of the Shields Company

Correct Answer: Delays by the Receiver of the Shields Company

Correct Answer Explanation: 40 days of work were lost due to delays by the Receiver of the Shields Company, a significant setback in the overall project schedule.

**What was the average quantity of dynamite used for advancing the main working faces in the Bergen Hill Tunnels?**

- 1 pound
- 2.5 pounds
- 5 pounds
- 10 pounds

Correct Answer: 2.5 pounds

Correct Answer Explanation: The average quantity of dynamite used for advancing the main working faces was 2.5 pounds.

**What was the depth of the shaft sunk at Central Avenue?**

- 100 feet
- 150 feet
- 212 feet
- 300 feet

Correct Answer: 212 feet

Correct Answer Explanation: A shaft 212 feet deep was sunk at Central Avenue, located 3,620 feet from the Weehawken Shaft.

**What was the main purpose of the Bergen Hill Tunnels?**

- To transport water
- To transport sewage
- To transport freight and passengers
- To transport oil

Correct Answer: To transport freight and passengers

Correct Answer Explanation: The Bergen Hill Tunnels were a crucial part of the Pennsylvania Railroad’s New York Tunnel Extension, designed to transport freight and passengers between New Jersey and New York City.

**What was the average quantity of powder used per cubic yard for the entire Bergen Hill Tunnel project?**

- 1 pound
- 2 pounds
- 2.9 pounds
- 4 pounds

Correct Answer: 2.9 pounds

Correct Answer Explanation: The average quantity of powder used on the entire work was about 2.9 pounds per cubic yard.

**What was the average rate of progress for each working face per day in the Bergen Hill Tunnels?**

- 1 foot
- 2 feet
- 3 feet
- 4 feet

Correct Answer: 3 feet

Correct Answer Explanation: The average rate of progress for each working face per day was 3.13 feet.

**What was the maximum output of a steam shovel in one shift?**

- 50 cubic yards
- 100 cubic yards
- 159 cubic yards
- 200 cubic yards

Correct Answer: 159 cubic yards

Correct Answer Explanation: The maximum output of a steam shovel in one shift was 159 cubic yards.

**What was the average depth drilled per hour while the drills were “actually working” in the Bergen Hill Tunnels?**

- 1 foot
- 1.5 feet
- 2.66 feet
- 4 feet

Correct Answer: 2.66 feet

Correct Answer Explanation: The average depth drilled per hour, during the time the drills were “actually working”, was 2.66 feet.

**What was the average length of heading driven per day worked in the North West section of the Central Shaft?**

- 2 feet
- 3 feet
- 4.4 feet
- 6 feet

Correct Answer: 4.4 feet

Correct Answer Explanation: The average length of heading driven per day worked in the North West section of the Central Shaft was 4.4 feet.

**What was the average time required to drill one foot of normal trap rock in the Bergen Hill Tunnels?**

- 10 minutes
- 15 minutes
- 20 to 25 minutes
- 30 minutes

Correct Answer: 20 to 25 minutes

Correct Answer Explanation: The average time to drill one foot of normal trap rock was 20 to 25 minutes.

**What was the average quantity of water flowing out of the tunnel drains after the completion of the lining?**

- 25 gallons per minute
- 50 gallons per minute
- 75 gallons per minute
- 100 gallons per minute

Correct Answer: 75 gallons per minute

Correct Answer Explanation: The quantity of water flowing out of the tunnel drains after the completion of the lining was 75 gallons per minute.

**What was the average length of heading driven per day worked in the North East section of the Central Shaft?**

- 2 feet
- 3.5 feet
- 4.5 feet
- 6 feet

Correct Answer: 4.5 feet

Correct Answer Explanation: The average length of heading driven per day worked in the North East section of the Central Shaft was 4.5 feet.

**What was the average rate of progress per day in the ordinary trap rock section at Weehawken?**

- 2 feet
- 3 feet
- 4.55 feet
- 6 feet

Correct Answer: 4.55 feet

Correct Answer Explanation: The average rate of progress per day in the ordinary trap rock section at Weehawken was 4.55 feet.

**What was the average rate of progress per day in the timbered section at Weehawken?**

- 1 foot
- 1.5 feet
- 2.3 feet
- 3 feet

Correct Answer: 2.3 feet

Correct Answer Explanation: The average rate of progress per day in the timbered section at Weehawken was 2.3 feet.

**What was the average rate of progress per day in the hard trap rock section at Weehawken?**

- 1.5 feet
- 2 feet
- 2.4 feet
- 3 feet

Correct Answer: 2.4 feet

Correct Answer Explanation: The average rate of progress per day in the hard trap rock section at Weehawken was 2.4 feet.

**What was the average rate of progress per day in the hard sandstone section at Weehawken?**

- 2.5 feet
- 3 feet
- 3.2 feet
- 4 feet

Correct Answer: 3.2 feet

Correct Answer Explanation: The average rate of progress per day in the hard sandstone section at Weehawken was 3.2 feet.

**What was the total “actual working time” of drills over 736 shifts?**

- 1,000 hours
- 2,000 hours
- 3,826 hours
- 5,000 hours

Correct Answer: 3,826 hours

Correct Answer Explanation: The total “actual working time” of drills over 736 shifts was 3,826 hours.

**What was the best week’s work at a working face, equivalent to 803 cubic yards?**

- 20 linear feet
- 30 linear feet
- 41.8 linear feet
- 50 linear feet

Correct Answer: 41.8 linear feet

Correct Answer Explanation: The best week’s work at a working face was 41.8 linear feet, equivalent to 803 cubic yards.

**What was the largest number of yards taken out in any one week from one working face, equivalent to 1,087 cubic yards?**

- 40 linear feet
- 50 linear feet
- 56.6 linear feet
- 60 linear feet

Correct Answer: 56.6 linear feet

Correct Answer Explanation: The largest number of yards taken out in any one week from one working face was 56.6 linear feet, equivalent to 1,087 cubic yards.

**What was the total linear feet of full-section tunnel equivalent to 3,238 cubic yards taken out in one week from four working faces?**

- 100 linear feet
- 150 linear feet
- 168.4 linear feet
- 200 linear feet

Correct Answer: 168.4 linear feet

Correct Answer Explanation: The total linear feet of full-section tunnel equivalent to 3,238 cubic yards taken out in one week from four working faces was 168.4 linear feet.

**What was the average time per foot drilled in the bench?**

- 20 minutes
- 30 minutes
- 36.6 minutes
- 45 minutes

Correct Answer: 36.6 minutes

Correct Answer Explanation: The average time per foot drilled in the bench was 36.6 minutes.

**What was the average depth drilled per hour in the bench?**

- 1 foot
- 1.5 feet
- 1.64 feet
- 2 feet

Correct Answer: 1.64 feet

Correct Answer Explanation: The average depth drilled per hour in the bench was 1.64 feet.

**What was the best average monthly output of a steam shovel?**

- 20 cubic yards
- 40 cubic yards
- 60 cubic yards
- 80 cubic yards

Correct Answer: 60 cubic yards

Correct Answer Explanation: The best average monthly output of a steam shovel was 60 cubic yards.

**What was the average quantity actually handled by a steam shovel per shift?**

- 50 cubic yards
- 70 cubic yards
- 90 cubic yards
- 100 cubic yards

Correct Answer: 90 cubic yards

Correct Answer Explanation: The average quantity actually handled by a steam shovel per shift was 90 cubic yards.

**What was the average actual advance per day worked in the bench and enlargement of the Central Shaft headings?**

- 5 feet
- 6 feet
- 7.2 feet
- 8 feet

Correct Answer: 7.2 feet

Correct Answer Explanation: The average actual advance per day worked in the bench and enlargement of the Central Shaft headings was 7.2 feet.

**What was the distance from the Weehawken Shaft where hand mucking was used?**

- 500 feet
- 750 feet
- 1,000 feet
- 1,250 feet

Correct Answer: 1,000 feet

Correct Answer Explanation: Hand mucking was used for a distance of 1,000 feet from the Weehawken Shaft.

**How much more excavation was taken out than what the contractor was required to excavate?**

- 10%
- 15%
- 28%
- 40%

Correct Answer: 28%

Correct Answer Explanation: The excavation was taken out 28% more than what the contractor was required to excavate.

**How much more excavation was taken out than what was paid for?**

- 10%
- 15%
- 20%
- 25%

Correct Answer: 10%

Correct Answer Explanation: The excavation was taken out 10% more than what was paid for.

**What was the specific gravity of the hardest trap rock found in the Bergen Hill Tunnels?**

- 2.6
- 2.8
- 2.98
- 3.2

Correct Answer: 2.98

Correct Answer Explanation: The specific gravity of the hardest trap rock found was 2.98.

**What was the average time the drills were “actually working” per shift in the Bergen Hill Tunnels?**

- 4 hours
- 5.2 hours
- 6 hours
- 7 hours

Correct Answer: 5.2 hours

Correct Answer Explanation: The average time the drills were “actually working” was 5.2 hours per shift.

**What was the depth that was sunk in the Central Shaft in 6 months?**

- 150 feet
- 175 feet
- 205 feet
- 250 feet

Correct Answer: 205 feet

Correct Answer Explanation: A depth of 205 feet was sunk in the Central Shaft in 6 months.

**What was the specific gravity of the normal trap rock found in the Bergen Hill Tunnels?**

- 2.5 to 2.7
- 2.85 to 3.04
- 3.0 to 3.2
- 3.2 to 3.4

Correct Answer: 2.85 to 3.04

Correct Answer Explanation: The normal trap rock in the tunnels had a specific gravity ranging from 2.85 to 3.04.

**What was the weight per cubic foot of the hardest trap rock found in the Bergen Hill Tunnels?**

- 150 pounds
- 175 pounds
- 186 pounds
- 200 pounds

Correct Answer: 186 pounds

Correct Answer Explanation: The hardest trap rock found in the tunnels weighed 186 pounds per cubic foot.

**What was the weight per cubic foot of the normal trap rock found in the Bergen Hill Tunnels?**

- 150 to 170 pounds
- 160 to 180 pounds
- 179 to 190 pounds
- 180 to 200 pounds

Correct Answer: 179 to 190 pounds

Correct Answer Explanation: The normal trap rock in the tunnels weighed from 179 to 190 pounds per cubic foot.

**What was the distance between the Weehawken Shaft and Central Avenue?**

- 2,500 feet
- 3,000 feet
- 3,620 feet
- 4,000 feet

Correct Answer: 3,620 feet

Correct Answer Explanation: The distance between the Weehawken Shaft and Central Avenue was 3,620 feet.

**What was the length of each tunnel between the portals?**

- 4,000 feet
- 5,000 feet
- 5,920 feet
- 6,000 feet

Correct Answer: 5,920 feet

Correct Answer Explanation: The length of each tunnel between the portals was 5,920 feet.

**What was the grade of the Bergen Hill Tunnels?**

- 0.5%
- 1.0%
- 1.3%
- 1.5%

Correct Answer: 1.3%

Correct Answer Explanation: The tunnels have a grade of 1.3% ascending from east to west.

**Where are the Bergen Hill Tunnels located?**

- East of the Hudson River
- West of the Hudson River
- North of the Hudson River
- South of the Hudson River

Correct Answer: West of the Hudson River

Correct Answer Explanation: The Bergen Hill Tunnels are located west of the Hudson River and pass through a trap dike known as Bergen Hill.

**What was the temperature in the Bergen Hill Tunnels?**

- 40 to 50 degrees
- 50 to 60 degrees
- 60 to 70 degrees
- 70 to 80 degrees

Correct Answer: 50 to 60 degrees

Correct Answer Explanation: The temperature in the tunnels remained nearly stationary between 50° in winter and 60° in summer.

**What was the primary material used for the tunnel lining?**

- Brick
- Steel
- Stone
- Concrete

Correct Answer: Concrete

Correct Answer Explanation: The Bergen Hill Tunnels were lined with concrete, which provided strength and durability to the structure.

**What was the main purpose of the concrete lining?**

- To provide support for the tunnel walls
- To prevent water infiltration
- To improve ventilation
- All of the above

Correct Answer: All of the above

Correct Answer Explanation: The concrete lining served multiple purposes, providing support for the tunnel walls, preventing water infiltration, and improving ventilation.