When does the tank-vehicle chapter call for an inspection of the tanker?
Correct answer: Before loading, unloading or driving it.
Each operation can expose different problems. Inspect the vehicle and the tank equipment before loading, unloading or driving, not just after a spill or at the start of an occasional trip.
Source: Washington Commercial Driver Guide, N/10/20; section 8, introduction; physical PDF 107, printed 8-1. ↗
A tanker has just finished unloading. Before moving it, what must be checked about its intake, discharge and cutoff valves?
Correct answer: That they are sound and set correctly for vehicle movement.
Valve positions must suit the operation. A setting appropriate during a transfer may be unsafe for travel; follow the equipment procedure and verify the required closure and leak checks.
Source: Washington Commercial Driver Guide, N/10/20; section 8.1.1; physical PDF 107, printed 8-1. ↗
You know how to inspect one tanker but are assigned a different design. What should guide the additional inspection?
Correct answer: The operator's manual for the actual tank vehicle.
Tanks differ in equipment and operating arrangements. Use the actual vehicle's operator information to identify the valves, containment parts and special systems that need checking.
Source: Washington Commercial Driver Guide, N/10/20; section 8.1; physical PDF 107, printed 8-1. ↗
How should you decide whether the tanker's emergency equipment is adequate for the trip?
Correct answer: Identify the equipment required for that vehicle and verify it is present and working.
The guide directs drivers to find out what equipment their particular vehicle requires and check its condition. Requirements may depend on the equipment and cargo; this is not a universal one-item checklist.
Source: Washington Commercial Driver Guide, N/10/20; section 8.1.3; physical PDF 107, printed 8-1. ↗
A partially filled tank is brought to a stop. Why can the liquid still push on the vehicle afterward?
Correct answer: The moving liquid continues surging and pushes in the direction of its wave.
Vehicle and liquid motion do not end at exactly the same instant. The moving liquid can strike the end of the tank and disturb the vehicle's position or handling.
Source: Washington Commercial Driver Guide, N/10/20; section 8.2.2, continued on physical 108; physical PDF 107, printed 8-1. ↗
What distinguishes a baffle in the liquid-tank arrangement described by the guide?
Correct answer: It has openings that let liquid pass while reducing fore-and-aft surge.
Baffles interrupt and moderate the liquid's lengthwise movement while allowing flow through their openings. A sealed dividing bulkhead instead creates separate compartments.
Source: Washington Commercial Driver Guide, N/10/20; section 8.2.4; physical PDF 108, printed 8-2. ↗
Why is expansion space left above a bulk liquid load?
Correct answer: To accommodate liquid expansion as its temperature rises.
This space is called outage. Liquid can expand in transit as it warms; usable loading volume must allow for that expansion instead of filling every part of the tank.
Source: Washington Commercial Driver Guide, N/10/20; section 8.2.6; physical PDF 108, printed 8-2. ↗
Which group of factors should determine how much bulk liquid can be loaded?
Correct answer: Expansion allowance, liquid weight and applicable legal weight limits.
Check how much the liquid may expand, how much it weighs and the legal loading limits. Tank volume alone does not settle the safe and lawful amount to carry.
Source: Washington Commercial Driver Guide, N/10/20; section 8.2.7; physical PDF 108, printed 8-2. ↗
On a Washington CDL, which endorsement letter identifies tank-vehicle authorization?
Correct answer: N.
N is the tank endorsement. Read the endorsement field carefully: the same letter used as a passenger-vehicle restriction has a different meaning.
Source: RCW 46.25.080(2)(b)(iv); official text reviewed September 13, 2026. ↗
A CDL-required CMV carries four loaded 275-gallon IBCs temporarily attached to its chassis. Under FMCSA's guidance, are these treated as a tank-vehicle load?
Correct answer: Yes; each exceeds 119 gallons and together they are rated for 1,100 gallons.
The guidance includes multiple attached loaded IBCs meeting both capacity thresholds. Temporary attachment does not by itself exclude them.
Source: FMCSA, 49 CFR 383.5 Guidance Q&A 8, effective March 7, 2019; official text reviewed September 13, 2026. ↗
